Vehicular rearview mirror elements and assemblies incorporating these elements

ABSTRACT

The present invention relates to improved electro-optic rearview mirror elements and assemblies incorporating the same. Area of the effective field of view of the electro-optic mirror element substantially equals to that defined by the outermost perimeter of the element.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 13/431,700 filed on Mar. 27, 2012 and published as U.S.2012/023687, which is a continuation of U.S. patent application Ser. No.12/832,838 filed on Jul. 8, 2010 and now issued as U.S. Pat. No.8,169,684, which is a continuation-in-part of U.S. patent applicationSer. No. 12/750,357 filed on Mar. 30, 2010 and now abandoned, which is acontinuation of U.S. patent application Ser. No. 12/154,736, filed onMay 27, 2008 and now issued as U.S. Pat. No. 7,719,750, which is acontinuation of U.S. patent application Ser. No. 11/477,312 filed onJun. 29, 2006 and now issued as U.S. Pat. No. 7,379,225, which is acontinuation of U.S. patent application Ser. No. 11/066,903 filed onFeb. 25, 2005 and now issued as U.S. Pat. No. 7,372,611, which in turnclaims priority under 35 U.S.C. §119 to U.S. Provisional ApplicationNos. 60/548,472 filed on Feb. 27, 2004, and 60/605,111 filed on Aug. 27,2004, and 60/614,150 filed on Sep. 29, 2004. The U.S. patent applicationSer. No. 11/066,903 is also a continuation-in-part of U.S. patentapplications Ser. No. 10/260,741 filed Sep. 30, 2002 and now issued asU.S. Pat. Nos. 7,064,882 and Ser. No. 10/430,885 filed on May 6, 2003and now issued as U.S. Pat. No. 7,324,261. The disclosure of each of theabovementioned patent applications is incorporated herein by referencein its entirety.

BACKGROUND OF THE INVENTION

The present invention generally relates to electro-optic devices andapparatus incorporating such devices. In particular, the inventionrelates to electro-optic devices used in architectural windows orvehicular rearview mirror elements.

Electro-optic rearview mirror elements are becoming more common invehicular applications with regard to both inside and outside rearviewmirrors and mirror assemblies, whether on the driver's or thepassenger's side. Such electro-optic rearview mirrors are automaticallycontrolled to vary the reflectivity of the mirror in response torearward and forward aimed light sensors so as to reduce the glare ofheadlamps in the image reflected to the driver's eyes. Typicalelectro-optic elements, when incorporated in vehicular rearview mirrorassemblies, will have an effective field of view (as defined by relevantlaws, codes and specifications) that is less than the area defined bythe perimeter of the element itself. Often, the effective field of viewof the element is limited, at least in part, by the construction of theelement itself and/or an associated bezel.

Various attempts have been made to provide an electro-optic elementhaving an effective field of view substantially equal to the areadefined by its perimeter. Assemblies incorporating these elements havealso been proposed. FIG. 1A shows an exploded view of a portion of arearview mirror subassembly 100 as used in a typical exterior rearviewmirror assembly. As shown in FIG. 1B, the subassembly 100 includes anelectrochromic mirror element 110, a bezel 115, and a carrier plate 117.The subassembly may further include gaskets 120 and 122 that are placedon either side of electrochromic mirror element 110 to form a secondaryseal around the periphery of the mirror element 110. As shown in FIG.1B, electrochromic element 110 includes a front substantiallytransparent element 130 typically formed of glass and having a frontsurface 130 a and a rear surface 130 b. Electrochromic element 110further includes a rear element 140, which is spaced slightly apart fromthe element 130. A seal 146 is formed between elements 130 and 140 abouttheir periphery so as to define a sealed chamber 147 therebetween, inwhich an electrochromic medium is provided. Elements 130 and 140preferably have electrically conductive layers (serving as electrodes,not shown) on the surfaces facing the chamber such that an electricalpotential may be applied across the electrochromic medium. Theseelectrodes are electrically isolated from one another and separatelycoupled to a power source by means of first and second bus connectors148 a and 148 b. To facilitate connection of bus connectors 148 a and148 b, elements 130 and 140 are typically vertically offset so that onebus connector may be secured along a bottom edge of one of the elementsand another bus connector may be secured to the top edge of the otherelement. The bus connectors 148 a and 148 b are typically spring clips(similar to those disclosed in commonly-assigned U.S. Pat. Nos.6,064,509 and 6,062,920) and are configured to ensure that they remainphysically and electrically coupled to the electrode layers on theinward-facing surfaces of elements 130 and 140. Once the electrochromicelement 110 has been manufactured and bus clips 148 a and 148 battached, then the mirror subassembly 100 may be formed. As shown inFIGS. 1A and 1B, bezel 115 includes a front lip 151, which extends overa portion of the front surface 130 a of the front element 130.Typically, the front lip 151 extends over a sufficient portion of frontsurface 130 a to obscure a person's view of the seal 146 and protect theseal 146 from possible degradation caused by ambient UV light. Asapparent from FIG. 1B, the width D₁ of the front lip 151 of the bezel115 depends upon a number of factors including an offset distance D₂between the elements 130 and 140. The width D₁ may also depend on thedegree to which the bus connector clips 148 a and 148 b extend beyondthe peripheral edges of elements 130 and 140. Typical bezels in therelated art have a front lip with a width D₁ of 5 mm or more.

Prior to inserting the electrochromic mirror element 110 in the bezel115, an optional front gasket 120 may be provided behind the front lip151 so as to be pressed between the front surface 130 a of the frontelement 130 and the inner surface of the front lip 151 of bezel 50. Themirror element 110 is then placed in bezel 115 and an optional reargasket 122 may be provided along the periphery of the back surface ofelement 140. In lieu of, or in addition to front and/or rear gaskets120, 122 the bezel/mirror interface area may be filled or potted with asealing material such as urethane, silicone, or epoxy. A carrier plate117, which is typically formed of an engineering grade rigid plastic ora similar material as used for bezel 115, is then pressed against therear surface of element 140 with the gasket 122 compressed therebetween.A plurality of tabs 152 may be formed inside of the bezel such thatcarrier plate 70 is snapped in place so as to secure mirror element 110within the bezel. The carrier plate 117 is typically used to mount themirror subassembly within an exterior mirror housing. More specifically,a positioner (shown below as element 6540 in FIG. 65) may also bemounted within the mirror housing and mechanically coupled to thecarrier plate 117 for enabling remote adjustment of the position of themirror subassembly within the housing.

While the above-described structure is readily manufacturable, stylingconcerns have arisen with respect to the width of the front lip of thebezel of an electrochromic mirror subassembly. Specifically, the widthof the front lip of the bezel of an EC-mirror has been typically madewider than that of any bezel used on non-dimming (non-electro-optic)mirrors due to the need to obscure and hide from view a mutualpositional offset of elements 130 and 140 (introduced to accommodateelectrical buss clips) and the seal between the substrates. In fact, innon-dimming mirrors bezels are often not used at all. In some vehicles,only the exterior mirror on the driver's side is electro-optic, whilethe passenger side mirror is non-dimming. Thus, there exists the needfor an improved electro-optic mirror element and an improvedelectro-optic exterior mirror subassembly that has a reduced bezel frontwidth or that does not include a front bezel at all.

SUMMARY OF THE INVENTION

At least one embodiment of the present invention provides improvedelectro-optic mirror elements. A related embodiment has an effectivefield of view area substantially equal to the field of view associatedwith an area defined by the perimeter of the element.

At least one embodiment of the present invention provides improvedassemblies incorporating electro-optic elements. A related embodimenthas an effective field of view area substantially equal to the area ofthe element itself as defined by its outer most perimeter.

Other advantages of the present invention will become apparent whilereading the detailed description of the invention in light of thefigures and appended claims.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1A is an exploded perspective view of a portion of a conventionalexterior electro-optic mirror subassembly;

FIG. 1B is an enlarged cross-sectional view of the conventional exteriorelectro-optic mirror assembly shown in FIG. 1A;

FIG. 2 depicts a controlled vehicle;

FIG. 3A depicts an assembly incorporating an electro-optic element;

FIG. 3B depicts an exploded view of an outside rearview mirror;

FIG. 4 depicts an inside rearview mirror assembly incorporating anelectro-optic element;

FIG. 5 is a front elevational view schematically illustrating a rearviewmirror system constructed in accordance with the present invention.

FIG. 6A is an enlarged cross-sectional view, along the line III-III ofFIG. 5, of an embodiment of the present invention.

FIG. 6B is a top plan view of a second substrate, as may be used in anembodiment of FIG. 6A, having an electrode formed thereon.

FIG. 7 is an enlarged cross-sectional view of an embodiment of anelectro-optical element of the present invention.

FIG. 8A is an enlarged cross-sectional view of another embodiment of anelectro-optical element of the present invention.

FIG. 8B is an enlarged cross-sectional view of an electro-optic mirrorelement incorporating alternative aspects of an embodiment of theinvention.

FIG. 8C is an enlarged cross-sectional view of an alternative embodimentof an electro-optic mirror element of the invention.

FIG. 8D is an enlarged cross-sectional view of yet another alternativeembodiment of an electro-optic mirror element of the invention.

FIG. 9A shows a top plan view of the second substrate of an embodimentof the invention with an electrode layer formed thereon, as may be usedin the embodiment of FIG. 8.

FIG. 9B shows a top plan view of the embodiment of FIG. 9A thatadditionally has a seal disposed thereon.

FIG. 10A shows a top plan view of the second substrate of an alternativeembodiment of the invention with an electrode layer formed thereon, asmay be used in the embodiment of FIG. 8.

FIG. 10B shows a top plan view of the alternative embodiment of FIG. 10Athat additionally has a seal disposed thereon.

FIG. 10C offers an exploded view showing the first and second substrateswith electrodes formed thereon, as may be used in embodiments of anelectro-optic mirror element of the present invention.

FIG. 10D is a top plan view of the second substrate shown in FIG. 10Cand additionally having a seal formed thereon.

FIG. 11 provides an enlarged cross-sectional view of embodiments of anelectro-optic mirror element.

FIG. 12 is an enlarged cross-sectional view of an electro-optic mirrorelement according to another alternative embodiment of the presentinvention.

FIG. 13 is an enlarged cross-sectional view of an electro-optic mirrorelement incorporating aspects of a different embodiment of the presentinvention.

FIG. 14 is an enlarged cross-sectional view of an embodiment of anelectro-optic mirror element incorporating means for visually hiding aseal.

FIG. 15 is an enlarged cross-sectional view of an alternative embodimentof an electro-optic mirror element incorporating means for visuallyhiding a seal.

FIG. 16A is an enlarged cross-sectional view of another alternativeembodiment of an electro-optic mirror element incorporating means forvisually hiding a seal.

FIG. 16B is an enlarged cross-sectional view of yet another alternativeembodiment of an electro-optic mirror element incorporating means forvisually hiding a seal.

FIGS. 17 (A-C) depict a plan view of the first surface, a plan view ofthe fourth surface, and a section view of an embodiment of anelectro-optic element, respectively.

FIG. 17D depicts a plan view of the fourth surface of an embodiment ofthe invention.

FIG. 17E depicts a plan view of the second substrate of an embodiment.

FIG. 18 depicts an enlarged view of FIG. 17C.

FIG. 19 depicts a graph of color-related characteristics for variouselectro-optic element components.

FIG. 20A depicts a cross-sectional view of an embodiment of anelectro-optic mirror element incorporating a light source.

FIG. 20B depicts a cross-sectional view of an embodiment of anelectro-optic element incorporating tab portions for making contact tothe associated electrical conductive layers.

FIG. 21A is a front plan view of an embodiment of an electro-opticmirror element incorporating a substantially continuous perimeter edgeand having tab/recess portion for contact areas for connection to theassociated electrically conductive layers.

FIG. 21B is a front plan view of an embodiment of an electro-opticmirror element similar to that of FIG. 21A but having a morerectangular-shaped perimeter and having tab/recess portions on aninboard edge thereof.

FIG. 21C depicts an electro-optic mirror element having a frontsubstrate that is larger than the associated rear substrate.

FIG. 22A is an enlarged cross-sectional view of an alternativeembodiment of the invention.

FIG. 22B is an enlarged cross-sectional view of an electro-optic mirrorelement incorporating alternative aspects of an embodiment of thepresent invention.

FIG. 22C is a top plan view of a rear substrate having an electrodeformed thereon, as may be used in the electro-optic mirror element shownin FIG. 22B.

FIG. 22D is an enlarged cross-sectional view of an electro-optic mirrorelement incorporating an edge seal in accordance with an alternativeembodiment of the present invention.

FIG. 22E is an enlarged cross-sectional view of an electro-optic mirrorelement incorporating an edge seal in accordance with another embodimentof the present invention.

FIG. 23 is an enlarged cross-sectional view of an electro-optic mirrorelement incorporating aspects of yet another embodiment of the presentinvention.

FIG. 24 is an enlarged cross-sectional view of an electro-optic mirrorelement incorporating aspects of an additional embodiment of the presentinvention.

FIG. 25 is an enlarged cross-sectional view of an electro-optic mirrorelement incorporating an edge seal in accordance with a supplementaryembodiment of the present invention.

FIG. 26 is a top plan view of an electro-optic mirror element showingthe provision of an edge seal as utilized in various embodiments of thepresent invention.

FIG. 27 is an enlarged cross-sectional view of an electro-optic mirrorelement incorporating an edge seal in accordance with yet anotherembodiment of the present invention.

FIG. 28 is an enlarged cross-sectional view of an electro-optic mirrorelement incorporating an edge seal in accordance with one moreembodiment of the present invention.

FIG. 29 is an enlarged cross-sectional view of an electro-optic mirrorelement incorporating an edge seal in accordance with a substituteembodiment of the present invention.

FIG. 30A is a first enlarged cross-sectional view of an electro-opticmirror element incorporating an edge seal in accordance with anotherembodiment of the present invention.

FIG. 30B is a second enlarged cross-sectional view of an electro-opticmirror element incorporating an edge seal in accordance with theembodiment of FIG. 30A.

FIG. 31 is an enlarged cross-sectional view of an electro-optic mirrorelement incorporating an edge seal in accordance with another embodimentof the present invention.

FIG. 32 is an enlarged cross-sectional view of an electro-optic mirrorelement incorporating an edge seal in accordance with yet anotherembodiment of the present invention.

FIG. 33 is an enlarged cross-sectional view of an electro-optic mirrorelement incorporating an edge seal in accordance with a relatedembodiment of the present invention.

FIG. 34 is an enlarged cross-sectional view of an electro-optic mirrorelement incorporating an edge seal in accordance with another relatedembodiment of the present invention.

FIGS. 35 (A-N) depict various techniques for establishing externalelectrical connections to the second and third surface conductiveelectrodes.

FIGS. 36 (A-N) depict various embodiments of electrical clips forestablishing external electrical connections to the second and thirdsurface conductive electrodes.

FIGS. 37(A-M) depict various views of carrier/bezel assemblies for usewith electro-optic elements in a rearview mirror assembly.

FIGS. 38 (A-C) depict various views of an electro-opticelement/electrical circuit board interconnection.

FIG. 39 is an enlarged cross-sectional view of an embodiment of theinvention incorporating a bezel.

FIG. 40 is an enlarged cross-sectional view of another embodimentincorporating a bezel.

FIG. 41 is a plot of bezel force vs. deflection for various materialsthat may be used to construct the bezel in an embodiment of the presentinvention.

FIGS. 42, 43, 43A-50 are enlarged fragmentary cross sectional views ofthe edge of corresponding additional mirror constructions, each having abezel aesthetically covering an edge of an electro-optic mirror element,the bezel being bonded to an edge of a carrier of the electro-opticmirror element in FIGS. 42-43A, 44, and mechanically interlockinglyengaging an edge of a carrier in FIGS. 45-50.

FIGS. 51-54 are enlarged fragmentary cross sectional views of the edgeof six additional mirror constructions, each having a bezelaesthetically covering a front of an edge of an electro-optic mirrorelement, the bezel in FIGS. 51-52 also covering a side of the edge, thebezel in FIGS. 53-54 only partially covering a side of the edge.

FIGS. 55-57 are enlarged fragmentary cross sectional views of the edgeof three additional mirror constructions, each having an edge of anelectro-optic mirror element coated by a strip of material, FIG. 55showing the strip extending from the front surface completely across aside, FIG. 56 showing the strip extending from the front surfacepartially onto a side, FIG. 57 showing the strip limited to the secondsurface of the electro-optic mirror element.

FIGS. 58-59 are enlarged fragmentary cross sectional views of a bezelhaving a C-shaped cross section that covers a side edge of theelectro-optic mirror element and that wraps onto the first and fourthsurfaces of the electro-optic mirror element, but also that includes aresiliently flexible fin that extends laterally away from theelectro-optic mirror element into wiping contact with a mirror housing.

FIG. 60 depicts a plan view of a carrier plate with an integral inboardcarrier;

FIG. 61 depicts a profile view of the carrier plate with an integralinboard carrier of FIG. 52.

FIG. 62 depicts a front view of an interior rearview mirror assembly.

FIG. 63 depicts a sectional view of an interior rearview mirrorassembly.

FIG. 64 depicts an exploded view of an interior rearview mirrorassembly.

FIG. 65 depicts an exploded view of an exterior rearview mirrorassembly.

FIGS. 66(A-E) illustrate embodiments of patterning of an eye-hole of arearview assembly.

FIG. 66F provides illustration to segregation effects in an EC element.

FIG. 66G shows examples of transmittance changes for EC elements withand without segregation.

FIG. 66H provides examples of % full scale behavior of the EC elementduring clearing.

FIGS. 67(A-D) illustrate various modalities pertaining to embodiments ofthe invention. FIG. 67A: electrical contacting modalities; FIGS.67(B-D): embodiments of plug configurations.

FIG. 68 shows a bezel-less embodiment having an EC-element based mirrorsystem with a rounded edge.

FIGS. 69(A-C) provide illustrations related to another embodiment havingan EC-element based mirror system with a rounded edge.

FIGS. 70(A,B), 71(A-C), 72(A-C) show embodiments of invention having alipless frame of the mirror system.

FIGS. 73(A-C) illustrate embodiments with a user interface including anoptical interrupter.

FIG. 74 schematically shows an embodiment with a user interface havingthree line-of-sight sensors.

FIG. 75 illustrates an embodiment with a user interface employing anoptical reflective sensor.

FIG. 76 illustrates an alternative embodiment with a user interfaceemploying an optical reflective sensor.

FIGS. 77(A, B) show embodiments employing a user interface having an“on-glass” type of capacitive sensor.

FIGS. 78(A-C) show embodiments employing a user interface having a“through-glass” type of capacitive sensor.

FIGS. 79(A, B) show an embodiment employing a user interface having an“in-glass” type of capacitive sensor.

FIGS. 79(C-G) show embodiments employing a user interface having an“through-bezel” type of a capacitive sensor or a field sensor.

FIGS. 80(A-C) illustrate embodiment having a “capacitive conductivebezel” type of user interface.

FIG. 81 shows an embodiment where a user interface employs an opticalwaveguide element.

FIGS. 82(A,B) illustrate embodiments of a peripheral ring used withrearview assembly of the present invention. FIG. 82A: a single-bandperipheral ring; FIG. 82B: a multi-band peripheral ring.

FIG. 83A shows a specific embodiment of a mirror system of the inventionincluding a multi-band peripheral ring.

FIG. 83B illustrates a two-lite embodiment of an electro-optic (EO)element having a two-band peripheral ring and a double seal thecomponents of which correspond tom the two bands.

FIG. 83C illustrates a non-specularly reflecting peripheral ring of anembodiment of invention.

FIGS. 84(A-D) show various embodiments of a two-band peripheral ringused in w mirror system of a rearview assembly of the invention.

FIG. 85 illustrates a mask construction means used to fabricate anembodiment of a two-band peripheral ring of the invention.

FIG. 86 shows an embodiment of a two-band peripheral ring having anon-uniform thickness.

FIGS. 87(A, B) illustrate an embodiment of a two-band peripheral ringwith a portion that is transflective. FIG. 87B: a sensor is positionedbehind the transflective portion of a two-band peripheral ring.

FIG. 87C illustrates transmission and reflection spectra of oneembodiment of a transflective thin-film stack used on a second surfaceof the mirror system of the invention.

FIGS. 88(A-D) illustrate alternative embodiments and uses of atransflective multi-band peripheral ring of the invention.

FIGS. 89(A-C) show variations in reflectance values as functions of realand imaginary parts of refractive index of a metal layer used forreflectance-enhancement in three corresponding embodiments of theinvention.

FIGS. 90(A, B) illustrate a derivation of formula facilitating thedetermination of a metallic material for reflectance-enhancement inembodiments of the invention.

DETAILED DESCRIPTION OF THE INVENTION

Definitions: As used in this description and the accompanying claims,the following terms shall have the meanings indicated, unless thecontext otherwise requires:

“Transflective” describes an optical element or component that has auseful non-zero level of transmittance and also has a useful, non-zerolevel of reflectance in a specified spectral region. In the context ofan image-forming reflector, such as a mirror for viewing reflectedimages, for example, the viewer in front of the mirror may not onlyobserve an image of the ambient objects, formed in reflection from suchtransflective area but also receive information contained in thedisplayed image delivered with light from the light source locatedbehind the transflective area of the mirror.

The spectrum of light reflected (and that of light transmitted) by anembodiment of the mirror system of the invention can be tuned ormodified by adjusting the thickness of the reflectance-enhancing layers.The peak reflectance will vary with optical design wavelength and thiswill result in a change in color gamut of the reflected (andtransmitted) light. In discussing color distributions (i.e., spectra oflight), it is useful to refer to the Commission Internationale deI'Eclairage's (CIE) 1976 CIELAB Chromaticity Diagram (commonly referredto the L*a*b* chart or quantification scheme). The technology of coloris relatively complex, but a fairly comprehensive discussion is given byF. W. Billmeyer and M. Saltzman in Principles of Color Technology,2^(nd) Edition, J. Wiley and Sons Inc. (1981). The present disclosure,as it relates to color technology and uses appropriate terminology,generally follows that discussion. As used in this application, Y(sometimes also referred to as Cap Y), represents either the overallreflectance or the overall transmittance, depending on context. L*, a*,and b* can be used to characterize parameters of light in eithertransmission or reflection. According to the L*a*b* quantificationscheme, L* represents brightness and is related to the eye-weightedvalue of either reflectance or transmittance (also known as normalized YTristimulus value) by the Y Tristimulus value of a white reference,Yref: L*=116*(Y/Yref)−16. The a*-parameter is a color coordinate thatdenotes the color gamut ranging from red (positive a*) to green(negative a*), and b* is a color coordinate that denotes the color gamutranging from yellow and blue (positive and negative values of b*,respectively). For example, absorption spectra of an electrochromicmedium, as measured at any particular voltage applied to the medium, maybe converted to a three-number designation corresponding to a set ofL*a*b* values. To calculate a set of color coordinates, such as L*a*b*values, from the spectral transmission or reflectance, two additionalparameters are required. One is the spectral power distribution of thesource or illuminant The present disclosure uses CIE Standard IlluminantA to simulate light from automobile headlamps and uses CIE StandardIlluminant D₆₅ to simulate daylight. The second parameter is thespectral response of the observer. Many of the examples below refer to a(reflectance) value Y from the 1931 CIE Standard since it correspondsmore closely to the spectral reflectance than L*. The value of “colormagnitude”, or C*, is defined as C*=√{square root over((a*)²+(b*)²)}{square root over ((a*)²+(b*)²)} and provides a measurefor quantifying color neutrality. The metric of “color difference”, orΔC* is defined as ΔC*=√{square root over ((a*−a*′)²+(b*−b*′)²)}{squareroot over ((a*−a*′)²+(b*−b*′)²)}, where (a*, b*) and (a*′,b*′) describecolor of light obtained in two different measurements. Additional CIELABmetric is defined as ΔE*=(Δa*²+Δb*²+ΔL*²)^(1/2). The color valuesdescribed herein are based, unless stated otherwise, on the CIE StandardD65 illuminant and the 10-degree observer.

An optical element such as a mirror is said to be relatively colorneutral in reflected light if the corresponding C* value of the elementis generally less than 20. Preferably, however, a color-neutral opticalelement is characterized by the C* value of less than 15, and morepreferably of less than about 10.

As broadly used and described herein, the reference to an electrode or amaterial layer as being “carried” on a surface of an element refers tosuch an electrode or layer that is disposed either directly on thesurface of an underlying element or on another coating, layer or layersthat are disposed directly on the surface of the element.

The following disclosure describes embodiments of the invention withreference to the corresponding drawings, in which like numbers representthe same or similar elements wherever possible. In the drawings, thedepicted structural elements are not to scale and certain components areenlarged relative to the other components for purposes of emphasis andunderstanding. References throughout this specification to “oneembodiment,” “an embodiment,” or similar language mean that a particularfeature, structure, or characteristic described in connection with theembodiment is included in at least one embodiment of the presentinvention. Thus, appearances of the phrases “in one embodiment,” “in anembodiment,” and similar language throughout this specification may, butdo not necessarily, all refer to the same embodiment.

The described features, structures, or characteristics of the inventionmay be combined in any suitable manner in one or more embodiments. Forexample, to simplify a particular drawing of an electro-optical deviceof the invention not all thin-film coatings (whether electricallyconductive, reflective, or absorptive or other functional coatings suchas alignment coatings or passivation coatings), electricalinterconnections between or among various elements or coating layers,elements of structural support (such as holders, clips, supportingplates, or elements of housing, for example), or auxiliary devices (suchas sensors, for example) may be depicted in a single drawing. It isunderstood, however, that practical implementations of discussedembodiments may contain some or all of these features and, therefore,such coatings, interconnections, structural support elements, orauxiliary devices are implied in a particular drawing, unless statedotherwise, as they may be required for proper operation of theparticular embodiment. In the following description, numerous specificdetails are recited to provide a thorough understanding of embodimentsof the invention. One skilled in the relevant art will recognize,however, that the invention may be practiced without one or more of thespecific details, or with other methods, components, or materials.

Numbering of Structural Surfaces.

In describing the order of elements or components in embodiments of avehicular rearview assembly or a sub-set of a vehicular rearviewassembly, the following convention will be generally followed herein,unless stated otherwise. The order in which the surfaces of sequentiallypositioned structural elements of the assembly (such as substrates madeof glass or other translucent material) are viewed is the order in whichthese surfaces are referred to as the first surface, the second surface,the third surface, and other surfaces if present referred to inascending order. Generally, therefore, surfaces of the structuralelements (such as substrates) of an embodiment of the invention arenumerically labeled starting with a surface that corresponds to thefront portion of a rearview assembly and that is proximal to theobserver or user of the assembly and ending with a surface thatcorresponds to the back portion of an assembly and that is distal to theuser. Accordingly, the term “behind” refers to a position, in space,following something else and suggests that one element or thing is atthe back of another as viewed from the front of the rearview assembly.Similarly, the term “in front of” refers to a forward place or position,with respect to a particular element as viewed from the front of theassembly.

The present disclosure refers to U.S. Pat. Nos. 4,902,108; 5,128,799;5,151,824; 5,278,693; 5,280,380; 5,282,077; 5,294,376; 5,336,448;5,448,397; 5,679,283; 5,682,267; 5,689,370; 5,803,579; 5,808,778;5,818,625; 5,825,527; 5,837,994; 5,888,431; 5,923,027; 5,923,457;5,928,572; 5,940,201; 5,956,012; 5,990,469; 5,998,617; 6,002,511;6,008,486; 6,020,987; 6,023,229; 6,037,471; 6,049,171; 6,057,956;6,062,920; 6,064,509; 6,084,700; 6,102,546; 6,111,683; 6,111,684;6,129,507; 6,130,421; 6,130,448; 6,132,072; 6,140,933; 6,166,848;6,170,956; 6,188,505; 6,193,378; 6,193,912; 6,195,194; 6,222,177;6,224,716; 6,229,435; 6,238,898; 6,239,898; 6,244,716; 6,246,507;6,247,819; 6,249,369; 6,255,639; 6,262,831; 6,262,832; 6,268,950;6,281,632; 6,291,812; 6,313,457; 6,335,548; 6,356,376; 6,359,274;6,379,013; 6,392,783; 6,399,049; 6,402,328; 6,403,942; 6,407,468;6,420,800; 6,426,485; 6,429,594; 6,441,943; 6,465,963; 6,469,739;6,471,362; 6,504,142; 6,512,624; 6,521,916; 6,523,976; 6,614,579;6,471,362; 6,477,123; 6,521,916; 6,545,794; 6,587,573; 6,614,579;6,635,194; 6,657,767; 6,774,988; 6,816,297; 6,861,809; 6,968,273;6,700,692; 7,064,882; 7,287,868; 7,324,261; 7,342,707; 7,417,717;7,663,798 and D410,607. The present application also refers to theInternational Patent Applications nos. PCT/WO97/EP498; PCT/WO98/EP3862and U.S. patent application Ser. Nos. 60/360,723; 60/404,879;11/682,121; 11/713,849; 11/833,701; 12/138,206; 12/154,824; 12/370,909;12/629,757; 12/774,721. The disclosure of each of the abovementionedpatent documents is incorporated herein by reference in its entirety.All these patent documents may be collectively referred to herein as“Our Prior Applications”.

Referring initially to FIG. 2, there is shown a controlled vehicle 200having a driver's side outside rearview mirror 210 a, a passenger's sideoutside rearview mirror 210 b and an inside rearview mirror 215. Detailsof these and other features will be described herein. Preferably, thecontrolled vehicle comprises an inside rearview mirror of unitmagnification. A unit magnification mirror, as used herein, refers to amirror with a plane or flat reflective element producing an image havingperceived angular and linear sizes equal to those of the object. Aprismatic day-night adjustment rearview mirror wherein at least oneassociated position provides unit magnification is considered herein tobe a unit magnification mirror. Preferably, the mirror provides a fieldof view with an included horizontal angle measured from the projectedeye point of at least 20 degrees and a sufficient vertical angle toprovide a view of a level road surface extending to the horizonbeginning at a point not greater than 61 m to the rear of the controlledvehicle when the controlled vehicle is occupied by a driver and fourpassengers or the designated occupant capacity, if less, based on anaverage occupant weight of 68 kg. It should be understood that the lineof sight may be partially obscured by seated occupants or by headrestraints. The location of the driver's eye reference points arepreferably in accordance with regulation or a nominal locationappropriate for any 95th percentile male driver. Preferably, thecontrolled vehicle comprises at least one outside mirror of unitmagnification. Preferably, the outside mirror provides a driver of acontrolled vehicle a view of a level road surface extending to thehorizon from a line, perpendicular to a longitudinal plane tangent tothe driver's side of the controlled vehicle at the widest point,extending 2.4 m out from the tangent plane 10.7 m behind the driver'seyes, with the seat in the rearmost position. It should be understoodthat the line of sight may be partially obscured by rear body or fendercontours of the controlled vehicle. Preferably, the locations of thedriver's eye reference points are in accordance with regulation or anominal location appropriate for any 95th percentile male driver.Preferably, the passenger's side mirror is not obscured by an unwipedportion of a corresponding windshield and is preferably adjustable bytilting in both horizontal and vertical directions from the driver'sseated position. In at least one embodiment, the controlled vehiclecomprises a convex mirror installed on the passenger's side. Preferably,the mirror is configured for adjustment by tilting in both horizontaland vertical directions. Preferably, each outside mirror comprises notless than 126 cm of reflective surface and is located so as to providethe driver a view to the rear along an associated side of the controlledvehicle. Preferably, the average reflectance of any mirror, asdetermined in accordance with SAE Recommended Practice J964, OCT84, isat least 35 percent (40 percent for many European Countries). Inembodiments where the mirror element is capable of operating at multiplereflectance levels, the minimum reflectance level in the day mode shallbe at least 35 percent (40 percent when mirror is fabricated accordingto European standards) and the minimum reflectance level in the nightmode shall be at least 4 percent.

With further reference to FIG. 2, the controlled vehicle 200 maycomprise a variety of exterior lights, such as, headlight assemblies 220a, 220 b; foul condition lights 230 a, 230 b; front turn-signalindicators 235 a, 235 b; taillight assembly 225 a, 225 b; rear turnsignal indicators 226 a, 226 b; rear emergency flashers 227 a, 227 b;backup lights 240 a, 240 b and center high-mounted stop light (CHMSL)245.

As described in detail herein, the controlled vehicle may comprise atleast one control system incorporating various components that provideshared functions with other vehicle equipment. An example of one controlsystem described herein integrates various components associated withautomatic control of the reflectivity of at least one rearview mirrorelement and automatic control of at least one exterior light. Suchsystems may comprise at least one image sensor within a rearview mirror,an A-pillar, a B-pillar, a C-pillar, a CHMSL or elsewhere within or uponthe controlled vehicle. Images acquired, or portions thereof, by asensor may be used for automatic vehicle equipment control. The images,or portions thereof, may alternatively or additionally be displayed onone or more displays. At least one display may be covertly positionedbehind a transflective, or at least partially transmissive,electro-optic element. A common controller may be configured to generateat least one mirror element drive signal and at least one otherequipment control signal.

Exterior and Interior Rearview Assemblies.

Turning now to FIGS. 3 a and 3 b, various components of an outside (orexterior) rearview mirror assembly 310 a, 310 b are depicted. Asdescribed in detail herein, an electro-optic mirror element may comprisea first substrate 320 a, 320 b secured in a spaced apart relationshipwith a second substrate 325 via a primary seal 330 to form a chamberthere between. At least a portion of the primary seal is left void toform at least one chamber fill port 335. An electro-optic medium isenclosed in the chamber and the fill port(s) are sealingly closed via aplug material 340. Preferably, the plug material is a UV-curable epoxyor acrylic material. Also shown is a spectral filter material 345 a, 345b located near the periphery of the element. Generally, this opticalthin-film spectral filter material 345 a, 345 b is circumferentiallydisposed in a peripheral area, next to a correspondingperimeter-defining edge, of either of the first and the second surfaceof the system, and is configured as a ring. Such ring of the spectralfilter material will be interchangeably referred to herein as aperipheral ring. The electrical clips 350, 355 are preferably secured tothe element, respectively, via first adhesive material 351, 352. Theelement is secured to a carrier plate 360 via second adhesive material365. Electrical connections from the outside rearview mirror to othercomponents of the controlled vehicle are preferably made via a connector370. The carrier is attached to an associated housing mount 376 via apositioner 380. Preferably, the housing mount is engaged with a housing375 a, 375 b and secured via at least one fastener 376 b. Preferably,the housing mount comprises a swivel portion configured to engage aswivel mount 377 a, 377 b. The swivel mount is preferably configured toengage a vehicle mount 378 via at least one fastener 378 b. Additionaldetails of these components, additional components, theirinterconnections and operation are discussed below.

With further reference to FIG. 3 a, the outside rearview mirror assembly310 a is oriented such that a view of the first substrate 320 a is shownwith the spectral filter material 345 a positioned between the viewerand the primary seal material (not shown). A blind spot indicator 385, akeyhole illuminator 390, a puddle light 392, a turn signal 394, a photosensor 396, any one thereof, a subcombination thereof or a combinationthereof may be incorporated within the rearview mirror assembly suchthat they are positioned behind the mirror element with respect to theviewer. Preferably, the devices 385, 390, 392, 394, 396 are configuredin combination with the mirror element to be at least partially covertas discussed in detail within various references incorporated byreference herein. Additional details of these components, additionalcomponents, their interconnections and operation are further discussedin reference to FIG. 65, below.

Turning now to FIG. 4, there is shown an inside (or interior) rearviewmirror assembly 410, as viewed when looking at the first substrate 420,with a spectral filter material 445 positioned between the viewer and aprimary seal material (not shown). The mirror element is shown to bepositioned within a movable housing 475 and combined with a stationaryhousing 477 on a mounting structure 481. A first indicator 486, a secondindicator 487, operator interfaces 491 and a first photo sensor 496 arepositioned in a chin portion 490 of the movable housing. A firstinformation display 488, a second information display 489 and a secondphoto sensor 497 are incorporated within the assembly behind the mirrorelement with respect to the viewer. As described with regard to theoutside rearview mirror assembly, it is preferable to have devices 488,489, 497 at least partially covert. For example, a “window” may beformed in third and/or fourth surface coatings of the associated mirrorelement and configured to provide a layer of a platinum group metal(PGM) (i.e. iridium, osmium, palladium, platinum, rhodium, andruthenium) only on the third surface. Thereby, light rays impinging uponthe associated “covert” photo sensor “glare” will first pass through thefirst surface stack, if any, the first substrate, the second surfacestack, the electro-optic medium, the platinum group metal and, finally,the second substrate. The platinum group metal functions to impartcontinuity in the third surface conductive electrode, thereby reducingelectro-optic medium coloring variations associated with the window.

FIG. 5 shows a front elevational view schematically illustrating aninterior mirror assembly 510 and two exterior rearview mirror assemblies210 a and 210 b for the driver side and passenger side, respectively,all of which are adapted to be installed on a motor vehicle in aconventional manner and where the mirrors face the rear of the vehicleand can be viewed by the driver of the vehicle to provide a rearwardview. As mentioned above, the interior mirror assembly 410 and exteriorrearview mirror assemblies 210 a and 210 b may incorporate light-sensingelectronic circuitry of the type illustrated and described in theCanadian Patent No. 1,300,945, U.S. Pat. No. 5,204,778, U.S. Pat. No.5,451,822, U.S. Pat. No. 6,402,328, or U.S. Pat. No. 6,386,713 and othercircuits capable of sensing glare and ambient light and supplying adrive voltage to the electro-optic element. The disclosure of each ofthese patent documents is incorporated herein by reference in itsentirety.

Mirror assemblies 410, 210 a, and 210 b are essentially similar in thatlike numbers identify components of the inside and outside mirrors.These components may be slightly different in configuration, but theyfunction in substantially the same manner and obtain substantially thesame results as similarly numbered components. For example, the shape ofthe front glass element of inside mirror 410 is generally longer andnarrower than outside mirrors 210 a and 210 b. There are also somedifferent performance standards placed on inside mirror 410 comparedwith outside mirrors 210 a and 210 b. For example, inside mirror 410generally, when fully cleared, should have a reflectance value of about70 percent to about 85 percent or even higher, whereas the outsidemirrors often have a reflectance of about 50 percent to about 65percent. Also, in the United States (as supplied by the automobilemanufacturers), the passenger-side mirror 210 b typically has aspherically bent or convex shape, whereas the driver-side mirror 210 aand inside mirror 410 are presently required to be flat. In Europe, thedriver-side mirror 210 a is commonly flat or aspheric, whereas thepassenger-side mirror 210 b has a convex shape. In Japan, both outsidemirrors have a convex shape. While the focus of the invention isgenerally towards exterior mirrors, the following description isgenerally applicable to all mirror assemblies of the present inventionincluding inside mirror assemblies. Moreover, certain aspects of thepresent invention may be implemented in electro-optic elements used inother applications such as architectural windows, or the like, or evenin other forms of electro-optic devices.

An embodiment of a rearview mirror of the present invention may includea housing having a bezel 544, which may extend around the entireperiphery of each of individual assemblies 410, 210 a, and/or 210 b.However, as discussed below, the scope of the present invention alsoincludes embodiments having no bezel. When present, the bezel 544visually conceals and protects the buss connector and the seal. A widevariety of bezel designs are well known in the art, such as, forexample, the bezel taught and claimed in above-referenced U.S. Pat. No.5,448,397.

EXAMPLES OF EMBODIMENTS Various Embodiments, Including Embodiments ofElectrical Interconnects

In the following description of various embodiments, accompanied byFIGS. 6 through 16, references are made to only those elements andcomponents that are necessary for understanding of a particular featureof an embodiment being discussed. Corresponding drawings illustrate onlythese referenced elements and components while other elements (such asadditional thin-film coatings, for example) are omitted from thedrawings for clarity of the presentation. It would be understood,however, that such other elements are implied and not excluded from thescope of a particular embodiment being described, unless statedotherwise.

FIG. 6A shows a cross-sectional view 600 of an exterior mirror assembly210 (a or b) of FIG. 5, constructed in accordance with at least oneembodiment of the present invention. A shown, an embodiment of FIG. 6Aincludes a front substantially transparent element (such as a glasssubstrate, for example) 612 that corresponds to the outer, or front,portion of the mirror assembly 210 facing the driver and a rear element614 (such as another glass substrate, for example) that corresponds tothe back portion of the mirror assembly 210. The front element 612 has afront surface 612 a and a rear surface 612 b, and a rear element 614 hasa front surface 614 a and a rear surface 614 b. For clarity ofdescription of such a structure, the following designations will begenerally used hereinafter in this disclosure. The front surface 612 aof the front glass element 612 will be referred to as the first surface,and the back surface 612 b of the front glass element 612 as the secondsurface. The front surface 614 a of the rear glass element 614 will bereferred to as the third surface, and the back surface 614 b of the rearglass element as the fourth surface. Generally, therefore, the firstsurface corresponds to a front of the mirror element while the fourthsurface corresponds to a back of the mirror element. Similardesignations are used throughout this disclosure in description of anyembodiment. A chamber or gap 625 between the two elements 612 and 614 isdefined by an inner circumferential wall 632 of sealing member 616 a andlined with a layer of substantially transparent conductor electrode 628(carried on second surface 612 b) and a reflecting electrode 620(carried on third surface 614 a). An electrochromic medium 626 iscontained within the chamber 625. The edges of the elements 612 and 614preferably have a “zero offset” in a transverse direction, which as usedherein means they are on average less than about 1-mm from being inperfect alignment, or more preferably are within about 0.5-mm from beingin perfect alignment. The zero offset may extend (and be maintained)completely around the elements 612 and 614, or, alternatively, mayextend along portions thereof, such as along edge portions having a busconnector or electrical conductor for the electrochromic materialcircuit. In embodiments of the invention, such small or zero offset isemployed to further reduce a total width or size of the edge bezel (see,for example, items 3944 of FIG. 39, 4044 a of FIG. 40, 2282 of FIG. 22B,2282 b of FIG. 22E, 1366 of FIG. 23, or 4244-4244P of FIGS. 42-59).

The front transparent element 612 may be made of any material which issubstantially transparent to visible light and has sufficient strengthto be able to operate in the conditions commonly found in the automotiveenvironment (e.g., varying temperatures and pressures). The frontelement 612 is preferably a sheet of glass and may comprise any type ofborosilicate glass, soda lime glass, float glass, or any other material,such as, for example, a polymer or plastic, that is transparent in thevisible region of the electromagnetic spectrum. The rear element 614must meet the operational conditions outlined above, except that it doesnot need to be transparent in all applications, and therefore maycomprise polymers, metals, glass, ceramics. In a preferred embodiment,however, the rear element 614 is a sheet of glass.

As shown in FIG. 6A, the electrode 620 on the third surface 614 a issealably bonded to the electrode 628 on the second surface 612 b by aseal member 616 disposed near the outer perimeter of both the secondsurface 612 b and the third surface 614 a so as to keep the substrates612, 614 in a spaced-apart and parallel relationship. The seal member616 may incorporate any material that is capable of adhesively bondingcoatings on the second surface 612 b to coatings on the third surface614 a in order to seal the perimeter of the chamber 625 to prevent theleakage of the electrochromic material 626 from the chamber 625. Inalternative embodiments, as described below, the layer of transparentconductive coating 628 and/or the layer of electrode 620 may be removedfrom a portion of the chamber where the seal member is disposed. In sucha case, the seal member 616 should be configured to bond well to glass.

The performance requirements for a perimeter seal member 616 used in anelectrochromic device are similar to those for a perimeter seal used ina liquid crystal device (LCD), which are well known in the art. The sealmust have good adhesion to glass, metals and metal oxides; must have lowpermeabilities for oxygen, moisture vapor, and other detrimental vaporsand gases; and must not interact with or poison the electrochromic orliquid crystal material it is meant to contain and protect. Theperimeter seal can be applied by means commonly used in the LCDindustry, such as by silk-screening or dispensing. Because of theirlower processing temperatures, thermoplastic, thermosetting or UV curingorganic sealing resins are preferred. Such organic resin sealing systemsfor LCDs are described in U.S. Pat. Nos. 4,297,401, 4,418,102,4,695,490, 5,596,023, and 5,596,024. Because of their excellent adhesionto glass, low oxygen permeability and good solvent resistance,epoxy-based organic sealing resins are preferred. These epoxy resinseals may be UV curing, such as described in U.S. Pat. No. 4,297,401, orthermally curing, such as with mixtures of liquid epoxy resin withliquid polyamide resin or dicyandiamide, or they can be homopolymerized.The epoxy resin may contain fillers or thickeners to reduce flow andshrinkage such as fumed silica, silica, mica, clay, calcium carbonate,alumina, etc., and/or pigments to add color. Fillers pretreated withhydrophobic or silane surface treatments are preferred. Cured resincrosslink density can be controlled by use of mixtures ofmono-functional, di-functional, and multi-functional epoxy resins andcuring agents. Additives such as silanes, titanates, or sulfur orphosphorous compounds can be used to improve the seal's hydrolyticstability and adhesion, and spacers such as glass or plastic beads orrods can be used to control final seal thickness and substrate spacing.Suitable epoxy resins for use in a perimeter seal member 616 include,but are not limited to: “EPON RESIN” 813, 825, 826, 828, 830, 834, 862,1001F, 1002F, 2012, DPS-155, 164, 1031, 1074, 58005, 58006, 58034,58901, 871, 872, and DPL-862 available from Shell Chemical Co., Houston,Tex.; “ARALITE” GY 6010, GY 6020, CY 9579, GT 7071, XU 248, EPN 1139,EPN 1138, PY 307, ECN 1235, ECN 1273, ECN 1280, MT 0163, MY 720, MY0500, MY 0510, and PT 810 available from Ciba Geigy, Hawthorne, N.Y.;and “D.E.R.” 331, 317, 361, 383, 661, 662, 667, 732, 736, “D.E.N.” 354,354LV, 431, 438, 439 and 444 available from Dow Chemical Co., Midland,Mich. Suitable epoxy curing agents include V-15, V-25, and V-40polyamides from Shell Chemical Co.; “AJICURE” PN-23, PN-34, and VDHavailable from Ajinomoto Co., Tokyo, Japan; “CUREZOL” AMZ, 2MZ, 2E4MZ,C11Z, C17Z, 2PZ, 21Z, and 2P4MZ available from Shikoku Fine Chemicals,Tokyo, Japan; “ERISYS” DDA or DDA accelerated with U-405, 24EMI, U-410,and U-415 available from CVC Specialty Chemicals, Maple Shade, N.J.; and“AMICURE” PACM, 2049, 352, CG, CG-325, and CG-1200 available from AirProducts, Allentown, Pa. Suitable fillers include fumed silica such as“CAB-O-SIL” L-90, LM-130, LM-5, PTG, M-5, MS-7, MS-55, TS-720, HS-5, andEH-5 available from Cabot Corporation, Tuscola, Ill.; “AEROSIL” R972,R974, R805, R812, R812S, R202, US204, and US206 available from Degussa,Akron, Ohio. Suitable clay fillers include BUCA, CATALPO, ASP NC,SATINTONE 5, SATINTONE SP-33, TRANSLINK 37, TRANSLINK 77, TRANSLINK 445,and TRANSLINK 555 available from Engelhard Corporation, Edison, N.J.Suitable silica fillers are SILCRON G-130, G-300, G-100-T, and G-100available from SCM Chemicals, Baltimore, Md. Suitable silane couplingagents to improve the seal's hydrolytic stability are Z-6020, Z-6030,Z-6032, Z-6040, Z-6075, and Z-6076 available from Dow CorningCorporation, Midland, Mich. Suitable precision glass microbead spacersare available in an assortment of sizes from Duke Scientific, Palo Alto,Calif. The seal may be constructed in accordance with the teachings inU.S. Pat. Nos. 5,790,298 and 6,157,480, the disclosure of each of whichis incorporated herein by reference in its entirety.

Another suitable way to maintain precision spacing between the twopieces of glass is by adding plastic fibers to the seal material. Thesefibers if cut from monofilament in an aspect ratio of about 2.5-3 to 1(length to diameter) are particularly effective in keeping the twosubstrates from sliding during the seal cure process. The glass spheresact as ball bearings that can enable movement between the substratesduring seal cure. Plastic fibers made of high temperature polyester(PEN) or polyetherimide (Ultem) when added to the seal material ataround a 1% by weight loading help prevent substrate movement becausethey are randomly orientated and some will not be positioned to roll.These plastic spacers have another benefit in that they more closelymatch the thermal expansion of cured organic seal material andconsequently will generate less seal stress during thermal cycling.

In further reference to FIG. 6A, the layer 628 of a substantiallytransparent electrically conductive material is deposited on the secondsurface 612 b to act as an electrode of the electrochromic device. Thesubstantially transparent conductive material 628 may be any materialwhich bonds well to the front element 612, is resistant to corrosioncaused by any materials within the electrochromic device, is resistantto corrosion by the atmosphere or road salts, has minimal diffuse orspecular reflectance, high light transmission, near neutral coloration,and good electrical conductance. The transparent conductive materialused for the layer 628 may be fluorine-doped tin oxide, doped zincoxide, indium zinc oxide (Zn₃In₂O₆), indium tin oxide (ITO),ITO/metal/ITO (IMI) as disclosed in “Transparent ConductiveMultilayer-Systems for FPD Applications,” by J. Stollenwerk, B. Ocker,K. H. Kretschmer of LEYBOLD AG, Alzenau, Germany; it may further includethe materials described in above-referenced U.S. Pat. No. 5,202,787,such as TEC 20 or TEC 15, available from Libbey Owens-Ford Co. ofToledo, Ohio, other transparent conductive metal oxides, or othertransparent conductors. Generally, the conductivity of the transparentconductive layer 628 will depend on its thickness and materialcomposition. In one embodiment, the layer 628 may include aninsulator-metal-insulator (IMI) film structure (or stack) that generallyhas superior conductivity compared with the other materials. The IMIstack, however, is known to undergo more rapid environmental degradationand suffer from interlayer delamination. The thicknesses of the variouslayers in the IMI structure may vary, but generally the thickness of thefirst insulator layer (e.g., ITO) ranges from about 10 Å to about 200 Å,the thickness of the metal layer ranges from about 10 Å to about 200 Å,and the thickness of the second insulator layer (e.g., ITO) ranges fromabout 10 Å to about 200 Å. If desired, an optional layer or layers of acolor suppression material (not shown) may be deposited between thelayer 628 and the second surface 612 b to suppress the reflection of anyunwanted portions of the electromagnetic spectrum.

In further reference to FIG. 6A, a reflector/electrode (or, reflectingelectrode) 620 includes reflecting layer(s) and electrically conductinglayer(s), referred to herein as a reflector/electrode or reflectingelectrode and is preferably disposed on the third surface 614 a. Thereflector/electrode 620 comprises at least one layer of a reflectivematerial, which serves as a reflecting layer and also forms an integralelectrode in contact with and in a chemically and electrochemicallystable relationship with any constituents in an electrochromic medium.The reflector/electrode 620 may be mostly reflective or may be partiallytransmissive/partially reflective (or “transflective”) as disclosed incommonly-assigned U.S. Pat. No. 6,700,692, the entire disclosure ofwhich is incorporated herein by reference. As an alternative, theelectrochromic device could incorporate a transparent electricallyconductive material on the third surface, which acts as an electrode,and incorporate a reflector on the fourth surface of an embodiment.However, combining the “reflector” and “electrode” into a reflectingelectrode 620 and placing both on the third surface is preferred becauseit makes the device manufacture less complex and allows the device tooperate at higher performance levels. The combined reflector/electrode620 on the third surface generally has higher conductivity than a singleconventional transparent electrode used on the third surface.

With respect to the transparent electrode 628, its material compositionmay be changed to generally lower its conductivity while maintainingcoloration speeds of the EC-element that are similar to those obtainablewith a fourth surface reflector device (this results in a substantialdecreased of the overall cost and time of production of anelectrochromic device). Improvement of performance of the device, on theother hand, may require a transparent electrode 628 on the secondsurface to have moderate to high value of conductivity. For thispurpose, materials such as ITO or IMI may be used for the constructionof the electrode 628. The combination of a high conductivity (i.e., theconductivity corresponding to sheet resistance of less than 250Ω/square, preferably less than 15 Ω/square and most preferably betweenapproximately 15 Ω/square and approximately 0.01 Ω/square) of thereflector/electrode 620 on the third surface and a high conductivity ofthe substantially transparent electrode 628 on the second surface willnot only result in an electrochromic device having more evendistribution of color across the device, but will also allow forincreased speed of coloration. Furthermore, in mirror assembliesutilizing a fourth surface reflector, both the electrode on the secondsurface and the electrode on the third surface are substantiallytransparent electrodes with relatively low conductivity. In previouslyused mirrors having third-surface reflector, there is a substantiallytransparent electrode and a reflector/electrode with relatively lowconductance and, as such, a long bus bar on the front and rear elementto bring current in and out is necessary to ensure adequate coloringspeed and coloring uniformity. In contradistinction, the third surfaceelectrode of at least some embodiments of the present invention aremetallic and may have a higher conductance and therefore has a very evenvoltage or potential distribution across the conductive surface, evenwith a small or irregular contact area. Thus, the present inventionprovides greater design flexibility by allowing the electrical contactfor the third surface electrode to be very small (if desired) whilestill maintaining adequate coloring speed and coloring uniformity.

In construction of outside rearview mirrors it is desirable to usethinner glass substrates in order to decrease the overall weight of amirror so that the mechanisms used to manipulate the orientation of themirror are not overloaded. Decreasing the weight of the deviceadditionally improves the dynamic stability of the mirror assembly whenit is exposed to vibrations. Alternatively, decreasing the weight of themirror element may permit more electronic circuitry to be provided inthe mirror housing without increasing the weight of the mirror housing.Thin glass may be prone to warpage or breakage, especially when exposedto extreme environments. In embodiments of the present inventionsubstantially this problem is substantially alleviated by the use of twothin glass elements and an improved gel material. Such improvedelectrochromic device is disclosed in commonly assigned U.S. Pat. No.5,940,201, the entire disclosure of which is incorporated herein byreference.

The addition of the combined reflector/electrode onto the third surfaceof the device further helps to remove any residual double or spuriousimaging resulting from the two glass elements having non-parallelsurfaces. Thus, chamber 625 preferably contains a free-standing gel thatcooperatively interacts with thin glass elements 612 and 614 to producea mirror that acts as one thick unitary member rather than two thinglass elements held together only by a seal member. In free-standinggels, which contain a solution and a cross-linked polymer matrix, thesolution is interspersed in a polymer matrix and continues to functionas a solution. Also, at least one solution-phase electrochromic materialis in solution in the solvent and therefore as part of the solution isinterspersed in the polymer matrix (this generally being referred to as“gelled electrochromic medium” 626). This allows one to construct arearview mirror with thinner glass in order to decrease the overallweight of the mirror while maintaining sufficient structural integrityso that the mirror will survive the extreme conditions common to theautomobile environment. This also helps maintain uniform spacing betweenthe thin glass elements, which improves uniformity in the appearance(e.g., coloration) of the mirror. This structural integrity resultsbecause the free-standing gel 626, the first glass element 612, and thesecond glass element 614, which individually have insufficient strengthcharacteristics to work effectively in an electrochromic mirror, arecoupled in such a manner that they no longer move independently but actas one thick unitary member. This structural integrity leads toincreased mechanical stability of the mirror that includes, but is notlimited to, resistance to flexing, warping, bowing and breaking, as wellas improved image quality of the reflected image, e.g., less distortion,double image, color uniformity, and independent vibration of each glasselement. However, while it is important to couple the front and rearglass elements, it is equally important (if not more so) to ensure thatthe electrochromic mirror functions properly. To assure suchperformance, the free-standing gel must bond to the electrode layers ofthe electrochromic element (including the reflector/electrode if themirror has a third surface reflector) on the walls of such a device, butat the same time not interfere with the electron transfer between theelectrode layers and the electrochromic material(s) disposed in thechamber 625. Further, the gel must not shrink, craze, or weep over timesuch that the gel itself causes poor image quality. Ensuring that thefree-standing gel bonds well enough to the electrode layers to couplethe front and rear glass elements and does not deteriorate over timewhile allowing the electrochromic reactions to take place as though theywere in solution, is an important aspect of the present invention. Whenusing a 1^(st) surface reflector around the perimeter of anelectro-optic mirror where the primary reflector is on one of the othersurfaces, the distance between the two reflective surfaces causes a darkshadow area to be formed when viewing the mirror from an angle. Theshadow increases in size with thicker substrates and decreases in sizefor thinner substrates. The shadow creates a region on discontinuousreflection and is undesirable when viewing an object in the mirror. Tominimize this shadow, the first substrate 612 with a thickness of lessthan 2.0 mm may be used. It is more preferred to use the first substrateof approximately 1.8 mm or less, and most preferred to use a firstsubstrate of approximately 1.1 mm or less.

To perform adequately, a mirror must accurately represent the reflectedimage, and this cannot be accomplished when the glass elements (to whichthe reflector is attached) tend to bend or bow while the driver isviewing the reflected image. The bending or bowing occurs mainly due topressure points exerted by the mirror mounting and adjusting mechanismsand by differences in the coefficients of thermal expansion of thevarious components that are used to house the exterior mirror element.These components include a carrier plate used to attach the mirrorelement to the mechanism used to manipulate or adjust the position ofthe mirror (bonded to the mirror by an adhesive), a bezel, and ahousing. Many mirrors also typically have a potting material as asecondary seal. Each of these components, materials, and adhesives hasvarying coefficients of thermal expansion that will expand and shrink tovarying degrees during heating and cooling and will exert stress on theglass elements 612 and 614. On very large mirrors, hydrostatic pressurebecomes a concern and may lead to double imaging problems when the frontand rear glass elements bow out at the bottom and bow in at the top ofthe mirror. By coupling the front and rear glass elements, the thinglass/free-standing gel/thin glass combination acts as one thick unitarymember (while still allowing proper operation of the electrochromicmirror) and thereby reduces or eliminates the bending, bowing, flexing,double image, and distortion problems and non-uniform coloring of theelectrochromic medium.

The cooperative interaction between the freestanding gel and the thinglass elements of the present invention also improves the safety aspectsof an electrochromic mirror having thin glass elements. In addition tobeing more flexible, thin glass is more prone to breakage than thickglass. By coupling the free-standing gel with the thin glass, theoverall strength is improved (as discussed above) and further restrictsshattering and scattering and eases clean-up in the case of breakage ofthe device.

An improved cross-linked polymer matrix used in at least one embodimentof the present invention is disclosed in commonly assigned U.S. Pat. No.5,928,572, the entire disclosure of which is incorporated herein byreference.

Typically, electrochromic mirrors are made with glass elements having athickness of about 2.3-mm. The preferred thin glass elements accordingto at least one embodiment of the present invention have thicknesses ofabout 1.1 mm, which results in a substrate weight savings of more than50 percent. This decreased weight ensures that the mechanisms used tomanipulate the orientation of the mirror, commonly referred to ascarrier plates, are not overloaded and further provides significantimprovement in the vibrational stability of the mirror.

Therefore, in at least one embodiment, the front transparent element 612is preferably a sheet of glass with a thickness ranging from 0.5 mm toabout 1.8 mm, preferably from about 0.5 mm to 1.6 mm, more preferablyfrom about 0.5 mm to 1.5 mm, even more preferably from about 0.8 mm toabout 1.2 mm, with the presently most preferred thickness about 1.1 mm.The rear element 614 preferably is a sheet of glass with a thickness inthe same ranges as element 612.

Vibrations that result from the engine running and/or the vehicle movingaffect the rearview mirror, such that the mirror essentially acts as aweight at the end of a vibrating cantilever beam. This vibrating mirrorcauses blurring of the reflected image, which is a safety concern aswell as a phenomenon that is displeasing to the driver. As the weight onthe end of the cantilever beam (i.e., the mirror element attached to thecarrier plate on the outside mirror or the mirror mount on the insidemirror) is decreased, the frequency at which the mirror vibratesincreases. If the frequency of the mirror vibration increases to around60 Hertz or greater, the blurring of the reflected image is not visuallydispleasing to the vehicle occupants. Moreover, as the frequency atwhich the mirror vibrates increases, the distance the mirror travelswhile vibrating decreases significantly. Thus, by decreasing the weightof the mirror element, the complete mirror becomes more vibrationallystable and improves the ability of the driver to view what is behind thevehicle. When both glass elements are made thin, the resistance tovibrations of an interior or exterior mirror improves, which isparticularly important for exterior mirrors. For example, an interiormirror with two glass elements having a thickness of 1.1 mm has a firstmode horizontal frequency of about 55 Hertz whereas a mirror with twoglass elements of 2.3 mm has a first mode horizontal frequency of about45 Hertz. This 10 Hertz difference produces a significant improvement inhow a driver views a reflected image.

A resistive heater (not shown in FIG. 6A) may be disposed on the fourthglass surface 614 b to heat the mirror and thereby clear the mirror ofice, snow, fog, or mist. The resistive heater may optionally be a layerof ITO, fluorine-doped tin oxide applied to the first and, or, fourthsurface, or may be other heater layers or structures well known in theart.

An electrical circuit such as those taught in the above-referencedCanadian Patent No. 1,300,945 and U.S. Pat. Nos. 5,204,778, 5,434,407,5,451,822, 6,402,328, and 6,386,713, is connected to and allows controlof the potential to be applied across electrode 620 and transparentelectrode 628, such that electrochromic medium 626 will darken andthereby attenuate various amounts of light traveling therethrough andthus vary the reflectance of the mirror containing electrochromic medium626. The electrical circuit used to control the reflectivity of theelectrochromic mirrors preferably incorporates an ambient light sensor(not shown) and a glare light sensor 515 of FIG. 5, the glare lightsensor being positioned either behind the mirror glass and lookingthrough a section of the mirror with the reflective material completelyor partially removed, or the glare light sensor can be positionedoutside the reflective surfaces (e.g., in the bezel 544) or, asdescribed below, behind a uniformly deposited transflective coating.Additionally, in some some area(s) of the mirror element the electrodes628, 620 may be partially or completely removed to permit alight-emitting display 545 of FIG. 5 (corresponding to a compass, clock,or other indicia) to show through the mirror element to the driver ofthe vehicle. Alternatively, as described below, this light-emittingdisplay assembly can be shown through a uniformly depositedtransflective coating. In one embodiment of the invention, a mirrorutilizes only one video chip light sensor to measure both glare andambient light and is equipped with means for determination of thedirection of glare. An automatic mirror on the inside of a vehicle,constructed according to this invention, can also control one or bothoutside mirrors as slaves in an automatic mirror system wherein theindividual mirror elements are independently controllable.

FIG. 6B shows a top plan view of the second transparent element 614 withthen reflecting electrode 620 deposited thereon, as may be used with thestructure shown in FIG. 6A. As shown, the electrode 620 is separatedinto two distinct electrode areas—a first portion 620 a and a secondportion 620 b that are electrically isolated and physically separated byan area 620 c, which is devoid of electrode material or any otherelectrically conductive material. As a result, no current flows from thefirst portion 620 a to the second portion 620 b of the electrode 620.Removal of the electrode material 620 from the area 620 c may beachieved, for example, by chemical etching, laser ablation, or scraping.Alternatively, the deposition of the electrode material in the area 620c can also be initially avoided by masking the area 620 c during thedeposition process.

As shown in FIG. 6A, the second portion 620 b of the electrode 620 is inelectrical contact with the electrochromic medium 626 at the thirdsurface 614 a of the electrochromic device. At the same time, the firstportion 620 a of the electrode 620 is physically isolated from theelectrochromic medium 626 by either the area 620 c, seal 616, or both.The first portion 620 a, however, is electrically coupled to a portionof the transparent electrode 628 on the second surface 612 b of theelectrochromic device by means of an electrical conductor, which mayextend around some or most of the periphery of the seal 616. Thus, ashort circuit is effectively provided between portions of the electrodelayers 620, 628. This short circuit allows the bus clip normallyattached to a peripheral edge of the first transparent element 612 to beattached instead to the second element 614. More specifically, as shownin FIG. 6B, an electrical connection between the power supply andtransparent electrode 628 on the second surface may be made byconnecting the bus bars (or clips 619 a) to the first portion 620 a ofelectrode layer 620. An electrical connection to the second portion 620b may be made using a clip 619 b that is attached to an extension 620 d,of the portion 620 b, that extends to the peripheral edge of the element614. Such configuration is advantageous in that it provides anelectrical connection to and communication with the transparentconductive material 628 nearly all the way around the circumference ofthe electrochromic element, which improves the speed of dimming andclearing of the electrochromic media 626. As will be described furtherbelow with respect to other embodiments, clips 619 a and 619 b may bereplaced with other types of electrical connectors.

FIG. 6A is drawn to simultaneously show two different implementations ofelectrical conductors providing for electrical coupling of the firstportion 620 a of the electrode 620 to a portion of electrode 628.Specifically, the left side of an embodiment 600 of FIG. 6A demonstratesthat conductive particles 616 b may be distributed through at least partof the seal material 616 such that a portion of the seal 616 iselectrically conductive. In one embodiment, the seal 616 is notelectrically conductive across its entire width, but rather has anon-conductive portion that electrically insulates the conductiveportion containing the conductive particles from the electrochromicmedium 626 and prevents a short circuit between the electrode 628 andsecond portion 620 b of the electrode 620. In this manner, the drivepotential from the power supply is provided through the first portion620 a of the electrode 620 and conductive particles 616 b in the seal616 before reaching the transparent conductor 628. In such aconfiguration, the seal 616 comprises a typical sealing material (e.g.,epoxy 616 a), with the conductive particles 616 b interdispersedtherein. The conductive particles may be small, such as, for example,gold, silver, copper, metal-coated plastic particles with a diameterranging from about 5 microns to about 80 microns, in which case theremust be a sufficient number of particles to ensure sufficientconductivity between the first portion 620 a of electrode 620 and thetransparent electrode 628. Alternatively, the conductive particles maybe large enough to act as spacers, such as, for example, gold, silver,copper, or metal-coated glass or plastic beads. The conductive particlesmay further be in the form of flakes or other suitable shapes orcombination of different shapes.

To ensure that no conductive particles 616 b are in contact with thearea 620 b of the reflecting electrode, a variety of methods may beused. For example, a non-conductive material may be disposed into thearea 620 c separating the portions 620 a and 620 b of the electrode 620.A dual dispenser could be used to deposit the seal 616 with conductiveparticles 616 b onto the first portion 620 a of the electrode 620 and tosimultaneously deposit the nonconductive material into the area 620 c.One general method of ensuring that no conductive particles reach theelectrode area 620 b is to make sure that the seal 616 has appropriateflow characteristics such that the conductive portion 616 b tends tostay behind as the sealant is squeezed out during the assembly process,and that only the non-conductive portion of the seal 616 flows into thearea 620 b. Another method would be to dispense the non-conductive sealmaterial(s) between the substrates, separately cure, or partially cure,the dispensed non-conductive seal, and then inject the conductive epoxybetween the two substrates.

In an alternative implementation, shown on the right side of theembodiment 600 of FIG. 6A, a larger electrical conductor 616 b isprovided, which may also serve as a spacer. Such a larger electricalconductor may be a single wire, a braided wire, a conductive strip, orsimply large particles or beads that are either electrically conductivethroughout or coated with an electrically conductive material. In thisimplementation, the seal 616 need not contain conductive particles orother electrical conductor 616 b and, instead, a conductive member ormaterial 616 c may be placed on or in the outer edge of the seal 616 tointerconnect the transparent conductive material layer 628 to the firstportion 620 a of the electrode 620. Alternatively, such a conductivemember 616 c may also be used in combination with conductors dispersedwithin the seal or otherwise between the elements 612 and 614.

Yet another embodiment 700 of an improved electrical interconnectiontechnique is illustrated in FIG. 7, where a seal member 616 is appliedin two steps. A first portion of a seal member is applied directly ontothe third surface 614 a and is cured prior to the application of theelectrode 620. After the electrode 620 is deposited onto the thirdsurface 614 a over the first portion of the cured seal member 616, aportion of the cured seal member 616 is machined off to leave asub-portion 616 i, as shown, having a predetermined thickness (whichwill vary depending on the desired cell spacing between the secondsurface 612 b and the third surface 614 a). Generally, the cell spacingranges from about 20 microns to about 1500 microns, and preferablyranges from about 90 microns to about 750 microns. By curing the firstportion of seal member and machining it to a predetermined thickness(616 i), the need for glass beads to ensure a constant cell spacing iseliminated. Although, as discussed above, glass beads are useful toprovide cell spacing, they provide mechanical stress at the points ofcontact with the electrodes 620 and 628. In absence of glass beads,these stress points are eliminated. During the machining of the curedfirst portion of the seal member 616, a portion of the electrode 620that is coated on the first portion of seal member is removed to leavean area devoid of the electrode layer 620. Subsequently, a secondportion of seal member 616 ii is deposited onto the machined area of thefirst portion of seal member 616 i or, alternatively, on the coatingscovering the second surface 612 b in the area corresponding to 616 i.The first and second substrates 612, 614 are then appropriatelyassembled, following by curing the second portion 616 ii of the sealmember 616. Finally, an outer electrically conductive seal member 717may optionally be deposited on the outer peripheral portion of the sealmember 616 to provide for an electrical contact between the outer edgeof the electrode 620 and the outer peripheral edge of the transparentconductive material layer 628. This configuration is advantageous inthat it provide for an electrical connection to the transparentconductive material 628 nearly all the way around the circumference ofthe embodiment of the device, and, therefore, improves the speed ofdimming and clearing of the electrochromic media 626.

Another implementation of electrical interconnections in an embodimentof the present invention is shown in FIG. 8A. This implementation 800differs from the embodiments of FIGS. 6A and 7 in that the electricalconductor connecting the first portion 620 a of the electrode 620 to aportion of the transparent electrode 628 is a wire or a strip 850 thatmay be coated with a conductive material 852 to improve contact to theelectrode layers 620, 628 and to thereby ensure contact stability. Theconductive material 852 may be conductive pressure-sensitive adhesive(PSA), conductive ink or an epoxy either of which may loaded withconductive particles, flakes, or fibers made of materials such assilver, gold, copper, nickel, or carbon. If the conductive material 852has sufficient conductivity, a wire/strip 850 would not be needed. Forcoloring uniformity it is desirable to keep the measured resistancealong the long edge of a mirror element below 5 Ohms, more preferablybelow 1 Ohm and most preferably below 0.5 Ohm. Many conductive inks oradhesives that are formulated for the electronics industry are suitablefor this application. The ink or adhesive is preferably filled withconductive flakes, fibers or particles or a combination thereof to havea sufficient filler loading and is deposited with sufficient width andthickness to achieve the desired level of conductivity. An epoxyadhesive formulation with suitable conductivity is (by weight) betweenapproximately 10% and approximately 20%, most preferably approximately13.5%, epoxy resin D.E.R. 354 or 354 LV (Dow Chemical Company), betweenapproximately 3% and approximately 7%, and most preferably approximately4.5%, Ancamine 2049 (Air Products and Chemicals Inc.) and betweenapproximately 70% and approximately 85%, and most preferablyapproximately 82%, sliver flake LCP 1-19 (Ames-Goldsmith). It ispreferable to keep the bulk conductivity of the filler material belowapproximately 20 microOhm-cm, more preferably below approximately 10microOhm-cm and most preferably below approximately 5 microOhm-cm.Similarly to the embodiments of FIGS. 6B and 7, the electrode 620 of theembodiment of FIG. 8 is separated into the first and second portions 620a, 620 b by an area 620 c that is devoid of any electrically conductivematerial.

FIG. 8B provides, in the same drawing, a showing of two alternativeimplementations of electrical interconnections that are related to theembodiment 800 of FIG. 8A. One implementation is shown on the left sideof a structure 860. Here, at least one portion of the peripheral edge ofthe front surface 614 a of the element 614 may be beveled to provide aheavy seam 854 between the elements 612 and 614. By forming this largeseam 854, a larger diameter wire 850 may be inserted between theelements 612 and 614, without otherwise having to increase the spacingbetween the elements 612 and 614 which would result in increase of thewidth of the chamber 625. Such a heavy seam 854 may be provided bybeveling either the front surface 614 a of the element 614 or the rearsurface 612 b of the front element 612. An alternative secondimplementation is shown on the right side of the structure 860. Here,rather than providing a single large diameter wire 850, a plurality ofsmaller-diameter wires 850′ or wire strands of a braided wire may beprovided as the electrical conductor between portions of the electrodes620 and 628. The use of wires twisted together makes it easier to applythe adhesive 852. The wires 850′ need not be made of the same material.For instance, a copper wire could be twisted with a stainless steel,nylon, KEVLAR, or carbon fiber or wire to impart strength or otherdesirable properties to the seal region of the embodiment of a mirrorelement. The seam 854 could extend, for example, 0.020 inch in from sideedges of the elements 612 and 614. Using the left portion of thestructure 860 as an example, although the seam could extend far enoughinto the device such that the nonconductive seal portion 616 would coverthe beveled portion of the electrode 620 b, it still would be beneficialto laser etch the region 620 c to ensure there is no electrical shortingbetween the electrodes 628 and 620 b through the conductive material852. It should be noted that if conductive adhesive 852 were ofsufficient conductivity, the wire 850 would not be necessary. In thiscase, the heavy seam 854 would allow for use of a greater amount of theconductive material 852 between the substrates 612, 614 to improve theoverall conductivity of the contact area.

FIG. 8C illustrates yet another embodiment of the present invention thatis similar to that shown in FIG. 8A. However, in comparison with theembodiment 800 of FIG. 8A, rather than etching a portion of electrode620 to provide for separate electrode regions 620 a and 620 b, anelectrically nonconductive coating or material 856 is disposed betweenthe electrode 620 and the coated wire 850. The coating or material 856could be formed of a thin layer of organic resin such as epoxy,polyester, polyamide, or acrylic, or of inorganic material such as SiO₂,Ta₂O₅, etc. Such a nonconductive material may also help to hold the wirein place.

FIG. 8D shows another embodiment of the present invention. As shown, notonly is the second substrate reflective electrode 620 etched in oneregion along a perimeter portion on the third surface, but also thetransparent electrode 628 on the second surface is configured in asimilar way. Specifically, the electrode 628 is etched to form a firstportion 628 a and a second portion 628 b separated by an area 628 c thatis devoid of conductive material. The transparent electrode 628 may beetched along any perimeter portion of the second surface which does notcoincide with the etching of electrode 620 over it's entire length. Thefront transparent electrode 628 may be etched along any side other thanthat on which electrode 620 is etched. Here, the edges of the elements612 and 614 would be even with one another (i.e., have zero-offset). Anelectrically nonconductive seal 616 would thus be formed about theperiphery and over the etched portions 628 c and 620 c of the twoelectrodes. The epoxy seal 616 would preferably be dispensed in from theedges of elements 612 and 614 approximately 0.010 to 0.015 inch on thetop and bottom and even with the glass edges on the sides. Theconductive material 852 could then be dispensed into the 0.010-0.015inch channel at the top and bottom of the device. A foil, copper webbingmaterial, or other highly conductive material 860 could then be adheredto the conductive epoxy/adhesive for each of the top and bottom regionsto provide for electrical contact to electrodes 620 and 628. The webbingwith its high surface area, or a foil, or thin conductive material withholes in it or roughened up exterior would enhance the adhesion of sucha material to the conductive material 852 and to the edges of thedevice.

Additional description of establishing the electrical interconnectionswithin the described-above embodiments of a mirror element is furtherprovided with respect to FIGS. 9 (A, B) and 10(A-D), in reference to topviews of the first and/or second substrates of the embodiments of amirror element.

FIG. 9A shows a top plan view of the rear element 614 having theelectrode coating 620 deposited thereon. To create the first and secondportions 620 a, 620 b, a portion of the electrode material may beremoved with the use of, e.g., laser ablation, chemical etching,physical scraping, or similar methods to form may be used to remove aportion of the electrode material to form the area 620 c that is devoidof any electrically conductive material. The area 620 c may be shapeddifferently, e.g. as a thin line that has a trench-like profile in theelectrode 620. As shown in FIG. 9A, the first portion 620 a is definedalong one side of the element 614. FIG. 9B shows the electricallynon-conductive seal 616 that is further disposed about the entireperiphery of the substrate 614 to define the outer bounds of the chamber625 in which the electrochromic medium 626 is disposed. The conductivematerial 852, which may in some embodiment also function as a sealingmember, is then disposed with or without a wire/strip 850 along theperipheral edge of the substrate 614 on which the first portion 620 a ofthe electrode 620 has been defined. Generally, the conductive material852 may be deposited prior to or after substrates 612 and 614 areassembled together.

An alternative implementation of the electrical interconnectionsdiscussed in reference to FIGS. 6A and 8 (A, B) is shown in top views ofthe substrate 614 in FIGS. 10A and 10B, where two first portions 620 a,620 a′ are defined at opposite sides of element 614 and separated by twocorresponding nonconductive separation areas 620 c, 620 c′. Such anarrangement would allow for an electrical connection to the electrode628 at two opposite sides of the element 614. The non-conducting seals616 and the material 852, which is also an electrically conducting sealin this embodiment, would be disposed in a similar manner but with theconducting seal 852 being dispensed over all or part of both portions620 a and 620 a′. The electrical wire(s) 850 (not shown) may extend fromthe conductive seal material 852 and be soldered to electrical clips ordirectly to a circuit board through which power is supplied to theelectrochromic mirror. To coat the wire and deposit it between thesubstrates 612 and 614, the wire 850 may be fed through the middle of adispensing nozzle that is used to dispense the seal material 852directly onto the required portion of coated element 614.

FIGS. 10C and 10D provide additional illustrations of an embodimenthaving a two-part (conductive and non-conductive) seal. Specifically,FIG. 10C illustrates etching of both electrodes 620 and 628, while FIG.10D shows the two portions 616′ and 616″ of the seal 616. The outerportion of the seal is conductive and the inner portion is nonconductivesimilar to the seal portions 616 a,b shown in FIG. 6A. (Although, in analternative embodiment, the entire seal 616 could be conductive and theelectrochromic device would function, such alternative construction isnot preferred with solution-phase electrochromic devices because of thesegregation of the electrochromic species is enhanced when coloration ofthe electrochromic media occurs on the inside edge of the conductiveseal and exposed portion of electrodes 628 a and 620 a.) As shown inFIG. 10D, there are two fill ports 1095 and 1096, provided at oppositeends of the electrochromic device, that allow for filling the chamber625 with electrochromic material and additionally provide for electricalisolation of the corresponding conductive portions of seal portions 616′and 616″. The plug material 1097 used to plug the fill ports 1095 and1096 would also be made of an electrically nonconductive material toprovide for the necessary electrical isolation. A fill port is typicallyplugged with an adhesive that is preferably UV-curable but that may alsobe a hot-melt or thermally-curable, or a combination of UV- andthermal-cure adhesive. The UV-curable adhesive generally is an acrylatebase, epoxy base or vinyl ether base or a combination thereof and isgenerally cured by free radical or cationic polymerization.

FIG. 11 shows another embodiment 1100 of the present invention. Thisembodiment, which would apply to both electrochromic mirror and windowapplications, includes the conductive seal material 852 deposited andcured on each of the electrodes 620 and 628. The electricallynonconductive seal 616 is then dispensed between the two portions of theconductive seal 852, which are applied respectively to the second andthird surfaces. The nonconductive seal 616 would be dispensed inward thegap 625 so as to provide for electrical isolation, if desired, betweenthe seal 852 and the electrochromic medium 626. Alternatively, a dualdispense could be used for simultaneously dispensing the conductive andnon-conductive seal materials. As a result, a portion of the height ofan aggregate seal is used as both the seal and the electricallyconductive bus. An advantage of this construction is that theseal/conductive bus 852 may extend about the entire periphery of theelectrochromic device for each of the two electrodes 620 and 628.Preferably, the conductive seal material 852 would be formed of epoxyloaded with silver.

Embodiment 1200 of FIG. 12 shows a slight variant to the embodiment 1100depicted in FIG. 11. Specifically, if the conductive material added tothe epoxy seal portions 852 is less environmentally friendly thansilver, the nonconductive seal could be formed either in two stages orusing two separate nonconductive seal materials. For example, thenonconductive epoxy seal 616 could be provided in the conventionalmanner between the electrochromic medium 626 and the two conductiveseals 852. Subsequently, a nonconductive material 1262 could be used tofill the gap between the conductive seal portions 852 and could extendalong the edge of glass elements 612 and 614. A benefit of using thisprocess is that the seal material 816 may be selected from thosematerials that are least susceptible to degradation from theelectrochromic medium while seal material 1262 could be selected frommaterials that are perhaps more moisture and oxygen impermeable.

FIG. 13 shows yet another embodiment of the present invention. Thisembodiment, which would be equally suitable for mirrors or windows,provides for a nonconductive seal 616 between the electrodes 628 and 620while defining the outer bounds of the chamber 625 in whichelectrochromic medium 626 is disposed. Between the seal 616 and the edgeof elements 612 and 614 is provided an electrically insulating material1364 made of ethylene-propylene-diene monomer (EPDM), polyester,polyamide, or other insulating material, and having conductive materials1366 such as a foil or copper web or other highly conductive materialattached to opposite sides thereof. Conductors 1366 may be secured toopposite sides of the insulator 1364 using a PSA. A conductive ink orepoxy 852 could be used to increase the contact stability between theconductors 1366 and electrodes 628 and 620. The seal 616 is notnecessary if materials 852, 1366, and 1364 provide for adequateenvironmental protection and do not interfere with the electrochromicmedium.

Concealment of the Seal.

FIG. 14 shows an enhancement to the embodiment described above withrespect to FIG. 8D. It will be appreciated, however, that thisenhancement approach may be used with any of the other embodimentsdescribed above or below. Specifically, as shown in an embodiment 1400,the structure of FIG. 8D is modified such that the first surface 612 ais beveled around its periphery to provide for a beveled peripheral edgesurface 1470 that is of sufficient width to obscure the view of the dualseal 616/852. With such a design, it may be possible to completelyeliminate the need in a bezel in an embodiment of the invention. As willbe appreciated by those skilled in the art, the conductive foil or web860 may extend rearwardly and wrap around the second substrate 614 forelectrical contact to a printed circuit board or the heater circuitthrough which power may be supplied to selectively vary the reflectivityof the mirror element. To further mask the view of the seal, areflective coating 1472 may be applied to the beveled surface 1470.

FIG. 15 shows a slightly different approach for obscuring the view ofthe seal (as shown, a non-conductive seal 616). Specifically, aperipheral portion 1575 of the first surface 612 a of the front element612 is sandblasted, roughened, or modified to obscure the view of theportion of the device where the seal could otherwise be seen. Yetanother approach is shown in FIG. 16A where a reflective or opaquepaint/coating 1676 is provided on the peripheral region 1575 of thefirst surface 612 a of the front element 612. Alternatively, as shown inFIG. 16B, such a reflective or opaque coating, paint, or film 1676 couldbe provided on the second surface 612 b.

Yet another way to conceal the seal is to use a seal material that istransparent as disclosed in commonly assigned U.S. Pat. No. 5,790,298,the entire disclosure of which is incorporated herein by reference.

Each of the different methods for obscuring the view of the sealdescribed above in connection with FIGS. 14-16B may be combined or usedseparately, and may be used with any of the other embodiments describedherein. For example, the beveled surface 1470 shown in FIG. 14 could besandblasted. Likewise, the sandblasted portion 1575 of the surface 612 acould be painted or coated with a reflective or high refractive indexmaterial. Paint or other material could be applied by silk-screening orother suitable methods. The reflective material in combination with theroughened surface provides a diffuse reflector.

Peripheral Ring and Sealing Material.

Turning now to FIGS. 17(A-E) and 18, a discussion of additional featuresof the present invention is provided. FIG. 17A depicts an embodiment ofthe rearview mirror element 1700 a, as viewed from the first substrate1702 a, with a spectral filter material 1796 a positioned between theviewer and a primary seal material 1778 a. A first separation area 1740a that is devoid of any electrically-conductive material is provided tosubstantially electrically insulate a first conductive portion 1708 afrom a second conductive portion 1730 a. A perimeter material 1760 a isapplied to the edge of the element. FIG. 17B depicts the same embodimentof a rearview mirror element, now labeled as 1700 b, as viewed from thesecond substrate 1712 b with a primary seal material 1778 b positionedbetween the viewer and a spectral filter material 1796 b, disposed as aperipheral ring. A second separation area 1786 b is provided tosubstantially electrically insulate a third conductive portion 1718 bfrom a fourth conductive portion 1787 b. A perimeter material 1760 b isapplied to the edge of the element. FIG. 17C depicts the same embodimentof a rearview mirror element, now labeled as 1700 c, viewed from asection line FIG. 17C-FIG. 17C of either the element of FIG. 17A or 17B.In this view, a first substrate 1702 c is shown to be secured to asecond substrate 1712 c in a spaced-apart relation via a primary sealmaterial 1778 c. A spectral filter material 1796 c is positioned betweenthe viewer and the primary seal material 1778 c. First and secondelectrical clips 1763 c, 1784 c, respectively, are provided tofacilitate electrical connections to the element. A perimeter material1760 c is applied to the edge of the element 1700 c. It should beunderstood that the primary seal material 1778 c may be applied by meanscommonly used in the LCD industry such as, e.g., by silk-screening ordispensing. U.S. Pat. No. 4,094,058 to Yasutake et al., the disclosureof which is incorporated in its entirety herein by reference, describesapplicable methods. Using these techniques, the primary seal materialmay be applied to an individually cut-to-shape substrate or it can beapplied as multiple primary seal shapes on a large substrate. The largesubstrate with multiple primary seals applied may then be laminated toanother large substrate and the individual mirror shapes can be cut outof the laminate after at least partially curing the primary sealmaterial. This multiple processing technique is a commonly used methodfor manufacturing LCDs and is sometimes referred to as an array process.Electro-optic devices can be made using a similar process. All coatingssuch as the transparent conductors, reflectors, spectral filters and, inthe case of solid state electro-optic devices, the electro-optic layeror layers may be applied to a large substrate and patterned ifnecessary. The coatings can be patterned using a number of techniquessuch as by applying the coatings through a mask, by selectively applyinga patterned soluble layer under the coating and removing it and thecoating on top of it after coating application, laser ablation oretching. These patterns can contain registration marks or targets thatcan be used to accurately align or position the substrates throughoutthe manufacturing process. This is usually done optically, for instance,with a vision system using pattern recognition technology. Theregistration marks or targets may also be applied to the glass directlysuch as by sand blasting, or laser or diamond scribing if desired.Spacing media for controlling the spacing between the laminatedsubstrates may be placed into the primary seal material or applied to asubstrate prior to lamination. The spacing media or means may be appliedto areas of the laminate that will be cut away from the finishedsingulated mirror assemblies. The laminated arrays can be cut to shapebefore or after filling with electro-optic material and plugging thefill port if the devices are solution phase electro-optic mirrorelements.

FIG. 17D depicts a plan view of a second substrate 1712 d comprising astack of materials on a third surface, or a fourth surface, or boththird and fourth surfaces. In at least one embodiment, at least aportion 1720 d 1 of a stack of materials, or at least the substantiallyopaque layers of a stack of materials, is removed, or masked, beneaththe primary seal material. At least a portion 1720 d 2 of at least alayer of the stack of materials extends substantially to the outer edgeof the substrate or extends to an area to facilitate electrical contactbetween the third surface stack and an element drive circuit (notshown). Related embodiments provide for inspection of the seal and, or,plug viewing and, or, plug curing the rear of the element subsequent toelement assembly. In at least one embodiment, at least a portion of anouter edge 1720 d 1 of a stack of materials 1720 d is located between anouter edge 1778 d 1 and an inner edge 1778 d 2 of a primary sealmaterial 1778 d. In at least one embodiment, the portion 1720 d 1 of astack of materials, or at least the substantially opaque layers of astack of materials, are removed, or masked, beneath the primary sealmaterial between approximately 2 mm and approximately 8 mm wide,preferably approximately 5 mm wide. At least a portion 1720 d 2 of atleast a layer of the stack of materials extends substantially to theouter edge of the substrate or extends to an area to facilitateelectrical contact between the third surface stack and an element drivecircuit (not shown) between approximately 0.5 mm and approximately 5 mmwide, preferably approximately 1 mm. It should be understood that any ofthe first, second, third and fourth surface layers or stacks ofmaterials may be configured as disclosed either below or in thereferences incorporated herein by reference.

FIG. 17E depicts a plan view of the second substrate 412E comprising athird surface stack of materials. In at least one embodiment, at least aportion of an outer edge 1720 e 1 of a third surface stack of materials1720 e is located between an outer edge 1778 e 1 and an inner edge 1778e 2 of a primary seal material 1778 e. In at least one relatedembodiment, a conductive tab portion 1782 e extends from an edge of thesecond substrate inboard of an outer edge 1778 e 1 of a primary sealmaterial 1778 e. In at least one related embodiment, a conductive tabportion 1782 e 1 overlaps with at least a portion of a third surfacestack of materials beneath a primary seal material 1778 e. In at leastone embodiment, a substantially transparent conductive layer (not shownindividually), such as a conductive metal oxide, of a third surfacestack of materials extends beyond an outer edge 1720 e 1 of a remainderof the third surface stack and is in electrical communication with aconductive tab portion as depicted in FIG. 35K. It should be understoodthat the conductive tab may be deposited along any of the substrateperipheral areas as shown in FIGS. 35D-35N. In at least one embodiment,a conductive tab portion comprises chrome. It should be understood thatthe conductive tab portion improves conductivity over the conductiveelectrode; as long as a conductive electrode layer is provided withsufficient conductivity, the conductive tab portion is optional. In atleast one embodiment, the conductive electrode layer imparts the desiredcolor-specific characteristics of the corresponding reflected light raysin addition to providing the desired conductivity. Therefore, when theconductive electrode is omitted, color characteristics are controlledvia the underlayer material specifications. It should be understood thatany of the first, second, third and fourth surface layers or stacks ofmaterials may be as disclosed herein or within the referencesincorporated elsewhere herein by reference.

FIG. 18 depicts an embodiment 1800 of a rearview mirror element, whichis an enlarged view of the element depicted in FIG. 17C to providegreater detail. The embodiment 1800 comprises a first substrate 1802having a first surface 1804 and a second surface 1806. A firstconductive electrode portion 1808 and a second conductive electrodeportion 1830 applied to the second surface 1806 are substantiallyelectrically insulated from one another via a first separation area1840. As can be seen, in at least one embodiment the separation area islocated such that the spectral filter material 1896 and a correspondingadhesion promotion material 1893 are also substantially electricallyinsulated to define first and second spectral filter material portions1824, 1836, respectively, and first and second adhesion promotionmaterial portions 1827, 1839, respectively. A portion of the firstseparation area 1840, (1740 a, 1740 b, 1740 c in FIG. 17) is shown to beextending parallel within a portion of the primary seal material 1878located near the center thereof. It should be understood that thisportion of the separation area 1840 may lie such that a viewer would notreadily perceive a line within the spectral filter material; forexample, a portion of the separation area may be substantially alignedwith an inboard edge 1897 of spectral filter material 1896. It should beunderstood that when any portion of the separation area 1840 is locatedinboard of the primary seal material, as is described in more detailelsewhere herein, a discontinuity in the electro-optic material coloringand, or, clearing may be observed. This operational characteristic maybe manipulated to derive a subjectively visually appealing element.

With further reference to FIG. 18, the embodiment 1800 is depicted tocomprise a second substrate 1812 having a third surface 1815 and afourth surface 1814. It should be noted that the first substrate may belarger than the second substrate to create an offset along at least aportion of the perimeter of the mirror. Third and fourth conductiveelectrode portions 1818, 1887, respectively, are shown proximate thethird surface 1815 and are substantially electrically insulated from oneanother via the second separation area 1886. A portion of the secondseparation area 1886 (1786 a, 1786 b, 1786 c in FIG. 17) is shown to beextending parallel within a portion of the primary seal material 1878located near the center thereof. It should be understood that thisportion of the separation area 1886 may lie such that a viewer would notreadily perceive a line within the spectral filter material; forexample, a portion of the separation area may be substantially alignedwith an inboard edge 1897 of spectral filter material 1796. As furthershown in FIG. 18, a reflective material 1820 may be applied between anoptional overcoat material 1822 and the third conductive electrodeportion 1818. It should be understood that any of the materials asdisclosed in commonly assigned U.S. Pat. Nos. 6,111,684, 6,166,848,6,356,376, 6,441,943, 6,700,692, 5,825,527, 6,111,683, 6,193,378,6,816,297, 7,064,882 and 7,324,261, the disclosure of each of which isincorporated herein by reference, may be employed to define a unitarysurface coating, such as a hydrophilic coating on a first surface, or acomposite stack of coatings, such as conductive electrode material,spectral filter material, adhesion promotion material, reflectivematerial, overcoat material applied to the first, second, third andfourth surfaces. It should be additionally understood that a hydrophobiccoating, such as a fluorinated alkyl saline or polymer, a siliconecontaining coating or a specially textured surface may be applied to thefirst surface. Either a hydrophilic or hydrophobic coating will alterthe contact angle of moisture impinging upon the first surface relativeto glass with no such coating and will enhance rear vision when moistureis present. It should be understood that both third surface and fourthsurface reflector embodiments are within the scope of the presentinvention. In at least one embodiment, the materials applied to thethird surface and, or, fourth surface are configured to provide apartially reflective/partially transmissive characteristic for at leasta portion of the corresponding surface stack. In at least oneembodiment, the materials applied to the third surface are integrated toprovide a combination reflector/conductive electrode. It should beunderstood that additional “third surface” materials may extend outboardof the primary seal, in which case, it should be understood that thecorresponding separation area extends through the additional materials.Having at least a portion of the primary seal visible from the fourthsurface, as depicted in FIG. 17D for example, facilitates inspection andUV curing of plug material. In at least one embodiment, at least aportion of a stack of materials 1720 d, or at least the substantiallyopaque layers of a stack of materials, are removed, or masked, beneaththe primary seal material to provide for inspection of at least 25percent of the primary seal width around at least a portion of theperimeter. It is more preferred to provide for inspection of 50 percentof the primary seal width around at least a portion of the perimeter. Itis most preferred to provide for inspection of at least 75 percent ofthe primary seal width around at least a portion of the perimeter.Various embodiments of the present invention will incorporate portionsof a particular surface having a coating or stack of coatings differentfrom other portions; for example, a “window” in front of a light source,information display, a photo sensor, or a combination thereof may beformed to selectively transmit a particular spectral band or bands ofwavelengths as described in many of the references incorporated herein.

With further reference to FIGS. 17 (A, B) and 18, the first separationarea 1840 cooperates with a portion of the primary seal material 1878 todefine the second conductive electrode portion 1830, the second spectralfilter material portion 1836 and the second adhesion promotion materialportion 1839 substantially electrically insulated from the firstconductive electrode portion 1808, the first spectral filter materialportion 1824 and first adhesion promotion material portion 1827. Thisconfiguration allows for placement of an electrically conductivematerial 1848 such that the first electrical clip 1863 is in electricalcommunication with the third conductive electrode portion 1818, thereflective material 1820, the optional overcoat 1822 and theelectro-optic medium 1810. It should be apparent, particularly inembodiments wherein the electrically conductive material 1848 is appliedto the element prior to placement of the first electrical clip 1869,that electrically conductive material may at least partially separatethe interfaces 1857, 1866, 1872, 1875. Preferably, the material, orcomposition of materials, forming the third conductive electrode portion1818, the first electrical clip 1863 and the electrically conductivematerial 1848 are chosen to promote durable electrical communicationbetween the clip and the materials leading to the electro-optic medium.The second separation area 1886 cooperates with a portion of the primaryseal material 1875 to define the fourth conductive electrode portion1887 substantially electrically insulated from the third conductiveelectrode portion 1818, the reflective layer 1820, the optional overcoatmaterial 1822 and the electro-optic medium 1810. This configurationallows for placement of an electrically conductive material 1890 suchthat the second electrical clip 1884 is in electrical communication withthe first adhesion promotion material portion 1893, the first spectralfilter material portion 1896, the first conductive electrode portion1808 and the electro-optic medium 1810. It should be apparent,particularly in embodiments wherein the electrically conductive material1890 is applied to the element prior to placement of the firstelectrical clip 1884, that electrically conductive material may at leastpartially separate the interfaces 1885, 1888, 1889. Preferably, thematerial, or composition of materials, forming the first conductiveelectrode portion 1808, the first electrical clip 1884, the adhesionpromotion material 1893, the spectral filter material 1896 and theelectrically conductive material 1890 are chosen to promote durableelectrical communication between the clip and the materials leading tothe electro-optic medium.

Preferably, the perimeter material 1860 is selected such that theresulting visible edge surface is visually appealing and such that goodadhesion is obtained at interfaces 1833, 1845, 1854. It should beunderstood that at least a portion of the first substrate 1802 in theareas proximate the first corner 1803, the edge 1805, the second corner1807 and combinations thereof may be treated to smooth protrusions anddepressions noticeable to a viewer. It is within the scope of thepresent invention to treat at least a portion of a surface, a corner, anedge or a combination thereof to define “beveled,” “rounded,” orcombinations thereof. Commonly assigned U.S. Pat. Nos. 7,064,882 and7,324,261 describe various mechanisms for carrying out the edgetreatment. The corresponding treatment improves the visual appearanceand durability of the element.

Turning to FIG. 19 and Tables 1-4-a, the color rendered as a result ofhaving an indium-tin-oxide (ITO) conductive electrode between the secondsurface of the first substrate and a spectral filter material (alsoreferred to herein as a “ring”) is described. In the example mirrorelement description contained herein, the reflectivity associated withthe spectral filter material with respect to that of the third surfacereflector results, in at least one embodiment, in a more blue hue forthe spectral filter material when the electro-optic medium is in a“clear” sate. As depicted in the tables contained herein, the b*associated with the reflector is higher than the b* associated with thespectral filter material. When there is mismatch between the hue of themain reflector and spectral filter material, it is often desirable tohave a spectral filter material with a lower b* value than the mainreflective area. Many outside mirrors are designed to have a bluish huein the main reflective area. As described in at least one embodimentherein, the use of aluminum in combination with, or in lieu of, chromefor the spectral filter material provides additional color renderingoptions. Other options, or embodiments, are depicted which provide abetter match between the ring and the mirror viewing area. In theseother cases the spectral filter or ring has virtually identicalreflectance and color allowing a seamless match between the viewing areaand the ring.

Table 1 summarizes various color characteristics, namely, Y specular(specular reflectance, R) included (A10); a*; b*; C* and Y specular(specular reflectance, R) excluded, for seven uniquely configuredspectral filter materials, second surface conductive electrode andrelated materials.

TABLE 1 D65-2 Macbeth Color Eye 7000 A10 D65-2 (specular included) Yspecular Reflectance Trial Y a* b* C* excluded 1 856csito 11.665 2.088−5.491 5.874 0.01 2 cswchr 38.312 −3.477 4.183 5.439 0.133 3 cswchral61.366 −3.108 6.965 7.627 0.186 4 halfchral 61.679 −4.484 12.279 13.0720.376 5 halfchr 41 −5.929 12.809 14.114 0.073 6 Tec15Chr 23.76 0.9848.603 8.659 1.322 7 Tec 15 11.284 −3.363 0.442 3.392 0.162 1 - Glass/856Ang. Al203/Half wave (Optical thickness) ITO 2 - 1 plus opaque chromelayer 3 - 1 plus approx 30 Ang. Chrome/250 Ang. Aluminum 4 - Glass/Halfwave ITO/30 Ang. Chrome/250Ang. Aluminum 5 - Glass/Half wave ITO/OpaqueChrome layer 6 - Glass/Tec15/Opaque chrome 7 - Tec 15

Tables 1a through 1d contain variations for the spectral filtermaterials. The reflectance is shown for a CIE-D65 standard illuminant.Individual layer thicknesses are shown in nanometers. Table 1a shows theeffect of chrome thickness on the stack Glass/ITO/Cr/Ru/Rh. Thereflectance of the stack increases as the thickness of the chrome isthinned. In this example the refractive index of the chrome is n=3.4559and k=3.9808, where n represents the real portion and k represents theimaginary portion of a complex number. The refractive index of thechrome in part defines the reflectivity of the stack and will bediscussed in more detail later. Also, as the chrome is thinned, thereflected a* values increase, leading to a better match for the ringmaterial.

In at least one embodiment, the reflectivity of the spectral filter isincreased by putting rhodium next to the first chrome layer instead ofruthenium. Table 1b shows the effect of chrome thickness on thereflectance and color of the ring as the chrome thickness is changed.Similarly to the previous example, the reflectance increases as thechrome layer is thinned. This embodiment is preferred when thereflectance of the center of the mirror reflectance is relatively high.

Typical production mirror properties are shown below:

FULL MIRROR REFERENCE COLOR Reflectance a* b* Typical Outside Mirror56.3 −2.2 2.4 Typical Inside Mirror 85.0 −3.0 5.0

TABLE 1a alternate stacks - chrome thickness with ruthenium R % Run #ITO Cr Ru Rh Cr Ru Rh (CIE-D65) a* b* 1 118 60 20 3.5 45.5 −6.1 −3.1 2118 20 20 3.5 47.5 −4.9 −2.8 3 118 10 20 3.5 50.24 −4.3 −2.3 4 118 5 203.5 51.16 −4.3 −2.1 5 118 2.5 20 3.5 51.17 −4.3 −1.9

TABLE 1b alternate stacks - chrome thickness with rhodium/ruthenium R %Run # ITO Cr Ru Rh Cr Ru Rh (CIE-D65) a* b* 17 118 0 5 30 59.82 −3.3−0.14 18 118 2.5 5 30 57.36 −3.2 −0.6 19 118 5 5 30 54.9 −3.3 −1.1 20118 7.5 5 30 52.64 −3.6 −1.6 21 118 10 5 30 50.66 −3.9 −2.2 22 118 12.55 30 49.02 −4.3 −2.6

Table 1c depicts the effect of ruthenium thickness when a thin rhodiumlayer is used next to a thin chrome layer. A particular benefit isattained when the ruthenium layer is approximately 20 nm. The minimumrequirement for ruthenium will vary with rhodium thickness, the thinchrome thickness and the target reflectivity value.

TABLE 1c alternate stacks - varying ruthenium behind rhodium R % Run #ITO Cr Ru Rh Cr Ru Rh (CIE-D65) a* b* 11 118 5 2.5 0 19.63 −8.5 −3.4 12118 5 2.5 10 44.46 −4.7 −2.8 13 118 5 2.5 20 52.9 −3.7 −1.6 14 118 5 2.530 53.97 −3.6 −1.3 15 118 5 2.5 40 53.4 −3.9 −1.6

Table 1d depicts the how the reflectance will change with rhodiumthickness at a fixed chrome and ruthenium thickness. The intensity ofthe reflectance increases with increasing rhodium thickness and thereflected a* increases. The increase in a* value of reflected light maybe exploited to help improve the color match between the center of glassand the ring. The change in reflectance with changing rhodium thicknesswill differ depending on the thickness of the chrome layer between therhodium and the ITO. The thicker the chrome layer, the more the rhodiumreflectance will be dampened. Also in Table 1d are alternate metalsbetween a thin and thick chrome layer. Palladium, iridium, cadmium andplatinum are shown. The reflectance versus metal thickness is shownalong with the effect of changing the thin chrome base layer thickness.

TABLE 1d alternate stacks - varying rhodium thickness R % Run # ITO CrRu Rh Cr Ru Rh (CIE-D65) a* b* 118 5 0 30 52.59 −4 −1.6 14 118 5 2.5 3053.97 −3.6 −1.3 16 118 5 5 30 54.9 −3.3 −1.1 19 118 5 7.5 30 55.5 −3.1−0.9 Glass 1.2 mm 1.2 mm 1.2 mm 1.2 mm 1.2 mm 1.2 mm ITO 120 120 120 120120 120 IRIDIUM 3 6 9 12 15 18 CR 40 40 40 40 40 40 R (cap Y) 50.5 52.854.3 55.4 56.0 56.4 ITO 120 120 120 120 120 120 Chrome 1 2 4 6 8 10IRIDIUM 15 15 15 15 15 15 CR 40 40 40 40 40 40 R (cap Y) 55.3 54.5 53.352.2 51.4 50.8 ITO 120 120 120 120 120 120 Palladium 3 6 9 12 15 18 CR40 40 40 40 40 40 R (cap Y) 50.9 53.6 55.6 57.0 58.0 58.7 ITO 120 120120 120 120 120 Chrome 1 2 4 6 8 10 Palladium 15 15 15 15 15 15 CR 40 4040 40 40 40 R (cap Y) 56.5 55.2 53.0 51.5 50.4 49.6 ITO 120 120 120 120120 120 Platinum 3 6 9 12 15 18 CR 40 40 40 40 40 40 R (cap Y) 49.7 51.352.3 52.9 53.1 53.2 ITO 120 120 120 120 120 120 Chrome 1 2 4 6 8 10Platinum 15 15 15 15 15 15 CR 40 40 40 40 40 40 R (cap Y) 52.3 51.6 50.549.7 49.2 48.9 ITO 120 120 120 120 120 120 Cadmium 3 6 9 12 15 18 CR 4040 40 40 40 40 R (cap Y) 52.3 56.5 59.9 62.5 64.6 66.1 ITO 120 120 120120 120 120 Chrome 1 2 4 6 8 10 Cadmium 15 15 15 15 15 15 CR 40 40 40 4040 40 R (cap Y) 62.2 60.1 56.6 54.0 52.0 50.7

Different metals or mixtures of metals may be used next to the thinchrome layer. The thin chrome layer may be considered optional.Generally, the thin chrome layer is used when an adhesion promoter layeris desired. Alternate adhesion promoting metals or materials may fulfilla comparable function. The different metals are selected to alter thereflectance, either higher or lower, depending on the match desired withrespect to the center of the viewing area. The metal can have anotherbenefit, that of altering the color or hue of the ring area. Thepresence of the ITO or other dielectric layer under the metals tends tomove the color to a more negative b* direction. The use of a “red” highreflectance metal such as copper may enhance reflectivity whilesimultaneously facilitating a color match to the viewing area. Table 1eshows the effect of a thin copper layer placed between two chromelayers. The reflectance is substantially increased while simultaneouslymaking the ring color more neutral. A copper gold alloy has similarproperties.

TABLE 1E Color and reflectance effects of copper addition to stack ITO114 114 Chrome 1 1 Copper 0 15 Chrome 40 40 R 47.3 56.2 a* −5.2 −0.7 b*−3.5 2.3

Suitable metals, which will result in increased reflectance, includecadmium, cobalt, copper, palladium, silver, gold, aluminum and iridiumor other high reflectance metals, their alloys and/or mixtures ofmetals.

Table 2 summarizes various color characteristics, namely, a*; b*; C* andreflectance (Y specular included (A10)) for the combinations of variousindium-tin-oxide second surface conductive electrodes positioned betweena first substrate and a substantially opaque chrome spectral filtermaterial. The data contained in this table depict the ability to controlthe resulting b* value by varying the ITO thickness from approximately65 percent to approximately 100 percent of a half-wave thickness.Specific thicknesses anticipated to obtain a given color may varysomewhat based on deposition parameters that affect the opticalconstants. The color of a particular stack may vary, to some degree,based on choice of process parameters, as well as process fluctuationsthat result in small but sometimes significant shifts in the opticalconstants of the materials used. For example, the half-wave opticalthickness of ITO will correspond to a lesser physical thickness if thephysical density of the coating is increased and an increase inabsorption in the ITO coating would decrease the reflectivity of asecond surface ITO plus chrome stack. This does not negate the fact thatover the range of optical constants usually associated with ITO, a halfwave optical thickness of ITO (relative to 550 nm) when coated with, forexample, chrome, will tend to produce a reflection having a yellowishhue. Table 2a shows the same effect over a narrower range of ITOthicknesses and with a modified metal stack. As the ITO is increased inthickness, the reflectance increases providing a better intensity match.The a* value decreases and the b* value increases. The net effect isthat the color match will be improved with the appropriate ITOthickness. Or, if a color mismatch is chosen, the color of the spectralfilter material can be made to have a lower b* value than the mainreflective area.

TABLE 2 TCO plus Chrome Specular Included Trial a* b* C* A10Y  85CHR−6.801 2.486 7.241 44.829  80CHR −6.717 −0.829 6.768 44.375  75CHR−6.024 −4.031 7.248 43.759  70CHR −5.613 −5.426 7.807 42.917  65CHR−5.227 −6.639 8.45 42.64 100CHR −7.06 12.85 14.662 45.255

TABLE 2a Effect of ITO with modified metal stack R % Run # ITO Cr Ru RhCr Ru Rh (CIE-D65) a* b* 108 5 2.5 30 52.3 −2.5 −4.5 113 5 2.5 30 53.2−3.1 −3.0 118 5 2.5 30 54.0 −3.6 −1.3 123 5 2.5 30 54.5 −4.1 0.6 128 52.5 30 54.9 −4.5 2.6 133 5 2.5 30 55.1 −4.7 4.7

Table 3 summarizes various color characteristics, namely, a*; b*; C* andreflectance R (Y specular included (A10)) for various indium-tin-oxidesecond surface conductive electrodes. The data contained in this tabledepicts the resulting values produced by varying the ITO thickness fromapproximately 65 percent to approximately 100 percent of a half-wavethickness.

TABLE 3 TCO Specular Included Y Thickness Trial a* b* C* (A10) (Å) 65CLR−0.988 15.535 15.567 15.678 1095 100CLR 13.588 −17.765 22.366 8.967 148085CLR 8.376 2.896 8.863 11.352 1306 80CLR 4.481 11.34 12.193 12.892 125375CLR 1.565 15.019 15.101 14.275 1194 70CLR −0.276 15.654 15.656 15.2591135

Materials used for transparent second surface conductive electrodes aretypically materials with an approximately 1.9 index of refraction, orgreater. It is known to minimize color impact of these conductiveelectrode materials by using half wave thickness multiples, using thethinnest layer possible for the application or by the use of one ofseveral “non-iridescent glass structures.” Non-iridescent structureswill typically use either a high and low index layer under the highindex conductive coating (see, for example, U.S. Pat. Nos. 4,377,613 and4,419,386 by Roy Gordon), or an intermediate index layer (see U.S. Pat.No. 4,308,316 by Roy Gordon) or graded index layer (see U.S. Pat. No.4,440,822 by Roy Gordon) to minimize color impact. The intensity of thering with a color suppression layer is lower than the center of thepart. The color suppression layer helps the color of the ring but thering would still be visible because of the intensity contrast. The colorsuppressed ITO would therefore benefit from the use of a differentsequence of metal layers on top of the ITO. Table 3a shows the color fora range of different metal options. The top chrome layer is optional andit does not contribute to the color or reflectance match of the ring.The top chrome layer is added to minimize the transmittance of the layerstack and to minimize the amount of UV light that would reach the seal,thus extending the lifetime of the product. A chrome/rhodium/rutheniumstack is shown but it is understood that other metals, alloys, and highreflectors described elsewhere in this document can be used.

The results of varying the thickness of the ITO with and without a colorsuppression layer are shown in Table 3a2. The colors shown in the tablerepresent the changes which occur with an ITO thickness between 100 and300 nm. Therefore, the use of a color suppression layer allows a broaderthickness range for the ITO layer without causing the strong colorvariations experienced without the color suppression layer.

TABLE 3a Effect of metal layers with color suppressed ITO - Reflectancein CIE-D65 Exam- Exam- Exam- Exam- Exam- Exam- Exam- Exam- Exam- Exam-Exam- ple 1 ple 2 ple 3 ple 4 ple 5 ple 6 ple 7 ple 8 ple 9 ple 10 ple11 Color Suppression Layer 80 80 80 80 80 80 80 80 80 80 80 ITO ½ Wave148.7 148.7 148.7 148.7 148.7 148.7 148.7 148.7 148.7 148.7 148.7 ChromeLayer 0 3 5 5 5 5 5 4 3 2 60 Rhodium 0 0 0 3 6 9 12 12 12 12 0 Ruthenium30 30 30 30 30 30 30 30 30 30 30 Chrome Layer 25 25 25 25 25 25 25 25 2525 0 Reflectance Cap Y 48.8 49.2 49.3 51.1 52.2 52.9 53.2 54.3 55.5 56.845.7 a* −2.2 −1.6 −1.4 −0.9 −0.5 −0.2 0.0 0.0 −0.1 −0.2 −1.8 b* 2.1 0.5−0.3 −0.3 −0.3 −0.2 −0.2 0.4 1.0 1.7 −3.3

TABLE 3a2 Effect of color suppressed ITO thickness on color - 200 nm ITO+/− 100 nm Stack Case 1 Case 2 Case 3 Case 4 Case 5 Case 6 Case 7 Case 81.670 80 80 80 80 80 80 80 80 ITO 100 130 150 180 210 240 270 300 Chrome2 2 2 2 2 2 2 2 Rhodium 5 5 5 5 5 5 5 5 Ruthenium 30 30 30 30 30 30 3030 a* 1.15 0.54 −0.76 −1.5 0 0.54 −0.84 −1.1 b* 0.9 0.14 1.7 3.22 0.92−0.16 2.17 3.1 1.670 0 0 0 0 0 0 0 0 ITO 100 130 150 180 210 240 270 300Chrome 2 2 2 2 2 2 2 2 Rhodium 5 5 5 5 5 5 5 5 Ruthenium 30 30 30 30 3030 30 30 a* −1 −3.9 −3.4 5.5 8 −4 −10.1 −0.9 b* −5.4 3.19 9.9 3.8 −8.6−4.3 7.6 5.5

A partially transmissive layer such as thin chrome adjacent to the glassmay be used to provide adhesion benefits compared to metals that mightbe used for better reflectivity compared to chrome such as a platinumgroup metal (PGM) (i.e. iridium, osmium, palladium, platinum, rhodium,and ruthenium), silver, aluminum and various alloys of such metals witheach other, such as silver-gold, white gold, or other metals. When theseother metals or alloys are placed behind the partially transmissiveadhesion promoting layer, some of the improved reflectance of the secondmaterial will be realized. It may also be beneficial to overcoat thespectral filter material with a material that improves the durability ofthe spectral filter material whether it is in contact with a transparentconductor overcoat or if it is in direct contact with the electro-opticmedium. It should be understood that the reflector may be a dichroicstack. The spectral filter material may comprise a single material suchas chrome or may comprise a stack of materials such as: 1) chrome,rhodium, ITO; 2) moly; 3) chrome, rhodium, TCO; 4) chrome, platinumgroup metal, ITO; 5) ITO, silver, ITO; 6) ITO, silver alloy, ITO; 7)Z_(N)O, silver/silver alloy, Z_(N)O; 8) transparent conductor, metalreflector, transparent conductor; silicon, ITO; 9) silicon, Z_(N)O; 10)chrome, ruthenium, ITO and 11) chrome/rhodium/ruthenium/ITO or othermetals, metal alloys or combinations described elsewhere in thisdocument can be used.

There may also be advantages to applying the transparent conductiveoxide(s) on the second surface of the mirror in more than one step. Forexample, a zinc oxide layer may be deposited initially to form a layerto which silver or its alloys bond well. This is preferably chosen at athickness that produced a desirable color and reflectivity when combinedwith silver, silver alloy or other metals and their alloys. Then themetal layer(s) are applied around the perimeter of the part followed byadditional transparent conductive oxide(s) over at least theelectrochromic area. The additional applications of oxides improve theconductivity in the electrochromic area and may be chosen at a thicknesswhich yields a desirable range of hue when going from bright state todark state, in the electrochromic area, but particularly in the fullydarkened state. If the conductive oxide adjacent to the electrochromicmedium has sufficient conductivity, not all of the metal oxides in thestack would necessarily need to be conductive.

For example, using an optical model, opaque silver deposited over 100 nmof ITO, the color of a reflective ring would be about, using CIELAB D65standard illuminant, 2 degree observer a*=−1, b*=−2 and Y value of 89.For purposes of this discussion, the silver is masked such that it isonly applied in a ring around the electrochromic area. The color of theelectrochromic area with only the 100 nm ITO on glass using a materialof index 1.43 as the electrochromic medium and no reflection from a3^(rd) or 4^(th) surface models as a*=−3, b*=8 with a Y value of 8. Tomake the electrochromic area less yellow and more conductive, 40 nm ofITO coating may be added in the electrochromic area. This brings thecoating in the electrochromic area to about half wave optical thickness,which is approximately the second surface coating thickness that mostelectrochromic elements have. The model for the electrochromic area thenyields a color of a*=11, b*=−14, and Y value of 5. Either, or both, ofthese applications of transparent conductive oxides may be of anothermaterial such as aluminum doped zinc oxide. There might also beadditional layer(s) such as nickel chromium or nickel chromium suboxide,niobium or niobium suboxide, titanium or titanium suboxide, as well asother means known in the art that would protect or preserve a metallayer such as silver during subsequent steps of the coating and assemblyprocess such as thermal processing steps.

Note that by using such a stack, the reflective ring will more closelymatch the brightness of electrochromic areas in the undarkened statethat are more highly reflective such as devices that have 3^(rd) surfacecoatings incorporating silver or silver alloys. In particular, aluminumthat is in direct contact with the electro-optic medium tends to degradeupon being subjected to multiple coloring/clearing cycles. An overcoatof chrome has been demonstrated to improve that durability. When an ITOovercoat is used, a material such as silicon may improve the strength ofthe bond between the ITO and the substances closer to the glass. Othermaterials, such as a platinum group metal (PGM) (i.e. iridium, osmium,palladium, platinum, rhodium, and ruthenium), may be overcoated toimprove any of adhesion, reflection, conductivity, and electrodestability characteristics of an embodiment. Not all material haveadequate durability to be used in configuring a peripheral ring on thesecond surface of the EC-element, which is usually maintained as ananode. For example, silver is known to be susceptible to de-plating whendeposited on the anodic side of an EC-cell and when exposed toEC-medium, but has adequate mechanical and electro-chemical stabilitywhen used as part of a reflective electrode on the third surface of theEC-cell that is typically maintained as a cathode. Therefore, in orderto expand a group of materials practically usable for construction of aperipheral ring, in one embodiment of the invention the transparentelectrode of an EC-cell is maintained as a cathode, while the reflectiveelectrode of the EC-cell is maintained as an anode.

As revealed in the above figures and tables, the thickness of ITO may bechosen to produce a desired reflection color. If the ITO coating isabout 25 percent thinner, that is about 120 Å. Instead of 140 Å, then amore bluish hue results (i.e. lower b*). This, however, will also resultin decreased conductivity of the ITO coating. The reflectivity of thecoating will also be slightly to somewhat higher than for coatings ofthe traditional half-wave optical thickness where the reference is to aminimum reflectivity near 550 nm.

The compromise between optimal color and sheet resistance of the ITO maybe mitigated by the use of partial deletion of the ITO layer. Forinstance, the ITO may be applied to any thickness needed to giveadequate color in the center of the viewing area and the required sheetresistance. Then, the ring portion of the ITO coating may be ion etchedor removed in any other viable method so that the final thickness of theITO in the ring is at a point where we have the desired aesthetics. Theetching or removal process for the ITO may be conducted in the sameprocess as the deposition of the subsequent metal layers or it may bedone in a separate step.

It is known in the art that a chrome layer may be applied beneath theITO layer to provide a marginal match between the viewing area and thering. The degree of match between the ring in this case and the viewingarea is a function of the reflectance in the viewing area and propertiesof the chrome. What has not been taught in the art is how the propertiesof the chrome layer affect the match of the ring to the viewing area.For instance, in some cases, the reflectance of the viewing area may bespecified by law to be greater than 55 percent. The reflectance of thechrome ring is a function of the thickness of the chrome and, moreimportantly, the refractive index of the chrome. For a given refractiveindex dispersion formula, the reflectance can be dropped from itsmaximum value by reducing the thickness of the chrome layer. This canhave a detrimental effect because the transmittance of the chrome layerwill increase thus allowing more UV light to penetrate to the EC unitseal. The UV light can damage the seal leading to a shorter lifetime ofthe product.

The reflectance of the ring may be enhanced by tuning the opticalproperties of the chrome layer. Table 3b shows the dependence of thereflectance of chrome under ITO on the optical properties of the chromelayer. Two sets of optical constants were obtained from the openliterature and were mixed in different proportions to assess the effectof the optical constants on the reflectivity. The optical constants varywith wavelength and the values in Table 3b are values at 550 nm forreference. The thickness of the chrome layer is 80 nm and the ITO is148.7 nm. In at least one embodiment, the glass thickness is 1.2 mm andthe reflectance quoted is for viewing through the glass to the coatingstack.

The reflectance, in this example, varies from a low of 48.6 to a high of54.2 percent. This clearly demonstrates that some chrome layers may notnecessarily attain the reflectance needed for a match to the reflectancein the viewing when relatively high reflectance is present in theviewing area. In addition, there is a finite maximum reflectanceattainable by a single layer of chrome under the ITO. The preferredchrome layers are defined by the refractive indices of the chrome layer.

TABLE 3b Performance of the chrome layer under ITO versus chrome forvarious chrome optical constants Chrome 80 80 80 80 80 (nm) Layer Chromen 3.456 3.366 3.279 3.196 3.116 @550 nm Chrome k 3.981 4.089 4.199 4.3104.423 @550 nm ITO-B18 148.7 148.7 148.7 148.7 148.7 (nm) Reflectance48.6 49.9 51.3 52.8 54.2 (percent)

In order to define the appropriate optical constants for the chromelayer, a series of calculations were performed. A simplified analysiswas conducted where the refractive index of the chrome is held constantover the visible region. The analysis shows the relationship between thereal and imaginary refractive indices of the chrome and the resultantreflectance. In actual practice, this may deviate from theoreticalanalysis by up to +/−20 percent to account for the effects of thedispersion in the chrome optical constants. Table 3c shows thereflectance for various combinations of n and k and the ratio of n/k.

TABLE 3c Reflectance for chrome under ITO as a function of the opticalconstants of the chrome @550 nm Example n k ratio Reflectance 1 3.003.90 0.77 49.8 2 3.00 4.10 0.73 51.7 3 3.00 4.20 0.72 52.7 4 3.00 4.200.71 52.7 5 3.00 4.30 0.70 53.7 6 3.00 4.50 0.67 55.5 7 2.70 4.20 0.6454.2 8 2.90 4.20 0.69 53.1 9 3.00 4.20 0.71 52.7 10 3.00 4.20 0.72 52.711 3.10 4.20 0.74 52.2 12 3.50 4.20 0.83 50.9 13 3.70 4.20 0.88 50.4 143.90 4.20 0.93 50.1 15 4.10 4.20 0.98 49.8 16 3.30 4.20 0.79 51.5 173.30 3.90 0.85 48.7 18 2.70 3.50 0.77 46.8 19 2.70 3.70 0.73 49.0 202.70 3.90 0.69 51.2 21 2.70 4.10 0.66 53.2 22 2.70 4.30 0.63 55.2 232.70 4.50 0.60 57.2 24 3.30 4.04 0.82 50.0

Analysis of this data set was conducted to determine an equationrelating n and k to reflectance. Again, the reflectance is calculatedwhen viewed through the glass.

Reflectance=9.21972−8.39545*n+20.3495*k+1.76122*n̂2−0.711437*k̂2−1.59563*n*k.

The results can also be shown graphically. Using the equation and/orgraph we can determine the needed n and k values necessary to attain adesired degree of reflectivity for a chrome layer.

Aesthetically, it is desirable for the ring to match the viewing area asclosely as possible. The eye is then not drawn to the ring and canbetter focus on the object in the viewing area. It is somewhatsubjective what difference in appearance between the ring and viewingarea is objectionable. The intensity between the ring and viewing areais preferably within 10 percent, more preferably within 6 percent andmost preferably within 3 percent. Similarly, the color of the ring maybe objectionable. The color difference between the ring and viewing areashould be less than 30, preferably less than 15 and most preferably lessthan 10 C* units.

There may be situations where, due to processing limitation orrestrictions, it is not possible to attain the desired chrome opticalconstants, but a match is still desired between the ring and the viewingarea. In other situations it may be desirable to attain a reflectancefor the ring which is higher than what is possible with chrome alone. Inthese circumstances an approach similar to what was discussed above forthe case of the metals on top of the chrome may be applied. To attainhigher reflectance, a relatively thin layer of chrome is applied to theglass followed by a higher reflecting metal layer such as rhodium,ruthenium, iridium, cadmium, palladium, platinum or other appropriatemetal or alloy which has an inherent higher reflectance than chrome.

Table 3d shows the effect of chrome thickness on the reflectance for afixed n and k value for the chrome layer. The optical constants for thechrome were selected to produce a reflectance less than 50 percent withthe goal to match a viewing area reflectance of 56 percent. Thereflectance varies with the thickness of the first chrome layer with,essentially, a perfect match when the chrome layer thickness is reducedto 2.5 nm.

TABLE 3d Chrome thickness effect on reflectance Modified stack tocompensate for change in chrome properties Chrome opticalconstants  n  3.456  k  3.981 Chrome Layer 40 30 20 10 5 2.5 (nm)Ruthenium 35 35 35 35 35 35 (nm) Chrome Layer 0 10 20 30 35 37.5 (nm)ITO-B18 148.7 148.7 148.7 148.7 148.7 148.7 (nm) Reflectance 48.4 48.549.7 52.8 54.9 55.8 (percent)

The optical constants of the chrome layer also have an effect on thereflectance of this stack. The reflectance may be attenuatedsignificantly with the optical constants of the chrome but with the useof a thin chrome layer backed by a higher reflectance metal layer,ruthenium in this case, the reflectance may be significantly increasedcompared to the case where the high reflectance metal is not present.Table 3e shows the effect of optical constants of the chrome on thereflectance.

TABLE 3e Effect of Chrome optical constants on reflectance Effect ofChrome base layer optical constants on reflectance Chrome Layer 10 10 1010 Ruthenium 35 35 35 35 Chrome Layer 30 30 30 30 ITO-B18 148.7 148.7148.7 148.7 Reflectance 53.5 54.9 55.9 56.9 Chrome n 3.366 3.279 3.1963.116 Chrome k 4.089 4.199 4.310 4.423

Another option for enhancing the reflectance of the ring and improvingthe aesthetic match to the viewing area consists of putting a low indexmaterial between the ITO and the metal layers. The low index layer maybe silica, alumina, MgO, polymer or other suitable low index material.At least options for the low index material exist. A first is to controlthe thickness of the silica layer to provide an interferential increasein reflectance. Table 3f compares the color of the ring with and withoutthe addition of the low index layer. In this case, the low index layeris silica but, as mentioned above, any appropriate low index material issuitable for this application. The thickness of the ITO and low indexlayers may be adjusted to alter the color while simultaneouslyincreasing the reflectance. The reflectance may be further increased bycombining this technique with the different metal stacks describedelsewhere in this document.

TABLE 3f Effect of addition of low index layer between the ITO and metallayers Case 1 Case 2 ITO 125 125 SIO2 0 55 Chrome 60 60 R 46.6 54.2 a*−6.6 −0.5 b* 0.9 3.0

Another option is to insert a relatively thick low index materialbetween the ITO and the metal reflectors of the ring. In this case, itis desirable that the low index layer to be thick enough to act as abulk layer. The necessary thickness is dependent, at least in part, onthe material properties of the bulk layer, particularly if theinhomogeneities help to eliminate the phase information of the light.The thickness of the layer may be as thin as ¼ micron or thicker to getthe desired effect.

Other options to provide a match between the ring and the viewing areainclude the use of a High/Low/High dielectric stack. A series ofdielectric layers with alternating refractive indices may be used toprovide a high reflectance coating. For example, TiO2/SiO2/TiO2alternating layers may be used. Table 3g shows a stack consisting ofTiO2, SiO2 and ITO (thicknesses in nm) which provides a reflectance ofthe ring of 60.5 percent with a neutral color. The color and reflectancemay be modified by adjusting the thickness of the layers. A secondoption, with ITO as the base layer, is also shown in Table 3g. The stackmay be adjusted with both configurations to give both the desired colorand reflectance values. The thickness of the ITO may be adjusted toprovide for a more conductive layer. The thickness and indices of theother layers may be adjusted to compensate for the changes in the ITOthickness. This increases the utility of this design option.

TABLE 3g High/Low/High stack for ring match Glass 1.6 mm Glass 1.6 mmTIO2 55.3 ITO 148.7 SIO2 94.5 SIO2 90 TIO2 55.3 TIO2 50 SIO2 94.5 SIO290 ITO 148.7 TIO2 55 Reflectance 60.5 Reflectance 60.7 a* −5.3 a* −4.9b* 5.64 b* −1.9

Another option for the ring is the use of an IMI, orinsulator/metal/insulator, stack for the electrode. Some particular IMIstacks and ring materials are noted below but other versions are alsoviable. In the context of this invention, it may be assumed that an IMIstack may be substituted for ITO or another TCO. A metal or dielectricstack is then put between the IMI stack and the substrate or the sealmaterial. Both scenarios will work well. When the reflecting stack isput between the IMI and the glass, a more flexible situation for the IMIstack is achieved, particularly if the metal reflectors are essentiallyopaque. The IMI is shielded by the metal reflectors and may be adjustedas needed for the center viewing area. When the IMI is in between theglass and the reflecting stack, it is desirable to ensure that therequirements in the viewing area and ring are compatible. This may beaccomplished but it does impose limitations on the IMI stack which arenot present when the reflectors are between the IMI and the glass.

In the IMI stack the insulator may be a dielectric layer such as TiO2,SiO2, ZnO, SnO2, Niobium oxide, silicon metal, ZrOx, SiN or othersuitable material. Mixed oxides, oxynitrides or other composites may beused. The metal is preferably Ag or an alloy of Ag. The Ag may bealloyed or doped with Au, Pd, Pt, Si, Ti, Cu or other materials selectedto provide the proper electrochemical, chemical or physical properties.Protective layers may be placed between the metal layer and thedielectrics to improve adhesion, chemical stability of the metal orthermal stability of the IMI coating during heat treatment. Multipledifferent dielectrics may be used to attenuate color and reflectance inthe viewing area and in the ring.

TABLE 3H IMI stacks and ring reflectance. Thicknesses are in nm unlessnoted Glass 1.6 mm Glass 1.6 mm Glass 1.6 mm Glass 1.6 mm Glass 1.6 mmGlass 1.6 mm Cr 45.0 Cr 30.0 Cr 20.0 Cr 0.0 Cr 0.0 Cr 40.0 ZnO 39.8 ZnO39.8 Ru 15.0 Ru 0.0 Ru 0.0 Ru 0.0 Ag 9.0 Ag 9.0 ZnO 39.8 ZnO 39.8 TiO223.5 TiO2 23.5 ITO 52.8 ITO 52.8 Ag 9.0 Ag 9.0 ZnO 10.5 ZnO 10.5 Cr 0.0Cr 0.0 ITO 52.8 ITO 52.8 Ag 9.0 Ag 9.0 R 54.2 R 53.2 Cr 0.0 Cr 10.0 ITO35.7 ITO 35.7 a* −4.9 a* −5.6 R 55.9 AL 40.0 Ru 0.0 Ru 0.0 b* 0.5 b* 1.3a* −4.3 R 57.5 Cr 25.0 Cr 0.0 b* 0.9 a* −1.5 R 54.3 R 55.1 b* 8.4 a*−3.4 a* −5.0 b* −0.2 b* 0.8

When the ITO thickness is increased from a half-wave to the point wherea bluish color is achieved for the ITO plus chrome stack, the color ismuch more susceptible to shifts due to thickness variations duringdeposition and/or due to viewing angle differences in actual use. ITOcoatings deposited intentionally thinner than half-wave opticalthickness, per the discussion above, also exhibited relatively lowlevels of haze when overcoated with chrome as depicted in Table 2.

The difference between coatings may be measured by using the specularexcluded option available on some reflectance spectrophotometers. It isimportant to check that such measurements are actually measuringscattered light and not primarily small amounts of the specularcomponent. In general, shorter wavelengths of light scatter morereadily. That fact is a good indicator when used to determine whether agiven reading is actually the expected scattered light intensity beingmeasured. A MacBeth Color Eye 7000 is one spectrophotometer that givesgood haze measurement results in this regard.

As used herein, the terms “haziness” and “haze” should be understood torefer to the property of scattering, or non-specular reflection, in thinfilms. Haziness may be caused by a number of factors, including, lessthan fully oxidized layers, crystal sizes within a layer, surfaceroughness, layer interface properties, quality of cleaning of thesubstrate, subcombinations thereof and combinations thereof.

These properties may vary due to processing conditions and/or thematerials. This is especially true with processing conditions, in thatthe level of haze may vary substantially even within a single process“batch” or “load” of coatings. Nonetheless, for an ITO layer overcoatedwith chrome and viewed through the glass, whether with or without colorsuppression or anti-iridescent underlayers, it has been shown to bepossible to produce coatings much less hazy than those similarlyobtained with Tec 15 glass from Libbey-Owens-Ford.

Aluminum oxide may be used as an underlayer to assist in controlling thehue of the spectral filter material stack, as well as mixtures of oxidesyielding an appropriate refractive index. It may be particularlyadvantageous to use a mixture of ITO and SiO₂ and/or SiO as anunderlayer for ITO to control the resulting hue of the spectral filtermaterial stack. The use of ceramic targets for ITO is often consideredcapable of tighter process control for properties such as filmthickness. A sputter target comprising ITO and Si and/or Si in a mixtureof oxidation states may be employed. Such an underlayer potentiallyenables one to use an in-line coating system that does not havesubstantial gas flow isolation from either pumping or intervening doorsbetween the cathodes used for depositing the underlayer and the ITOlayer. A mixture of ITO and SiO₂ to at least some percentage of SiO₂will retain sufficient conductivity such that RF sputtering is notnecessary. Radio Frequency (RF) sputtering, as compared to MediumFrequency (MF) sputtering or direct current (DC) sputtering, oftenrequires electrical isolation and impedance matching that is not trivialto include in a thin film coating system.

Since there are regulatory requirements for 35 percent (40 percent inmany European countries) reflectivity for vehicular rearview mirrors(clear state for electro-optic mirror elements), in order for theperimeter area to be included in the field of view calculations, itneeds to have such a level of reflectance. In the data provided hereinwith respect to chrome over Tec 15 glass, this minimum is not met.

Use of a measurably hazy CVD deposited flourine doped tin oxide that ispart of an anti-iridescent structure for use in electro-optic devices isknown. Various thicknesses of ITO are known for providing a conductiveelectrode. It has not previously been known that the b* of anindium-tin-oxide conductive electrode and chrome spectral filtermaterial stack may be predictably controlled by varying the thickness ofthe ITO. Pyrolitically deposited fluorine doped tin oxide with ananti-iridescent structure (Tec 15 from L.O.F) is substantially more hazywhen overcoated with chrome compared with ITO deposited over a layer ofaluminum oxide as shown in Table 1.

In embodiments where the spectral filter material is located proximatethe first surface, it can be advantageous to minimize the distancebetween the first surface and the third or fourth surface reflector. Thegreater the distance between the reflector and the first surface, thegreater the discontinuity will be in the image reflected by the elementwhen transitioning from the main reflector to the spectral filtermaterial. This will be accentuated as the viewing angle increases.

In embodiments where a spectral filter material is located proximate thesecond surface of the element and an additional coating, such as ahydrophilic coating, is on the first surface, the optical properties ofboth coatings will affect the appearance of the perimeter of the deviceand may require adjustments to the layers for optimal appearance of theperimeter. In the case of an electro-optic element with a hydrophiliccoating as described in commonly assigned U.S. Pat. Nos. 6,447,123,6,193,378 and 6,816,297 hereby incorporated in their entireties byreference, the first surface coating will have a reflectancesubstantially lower than the reflectance of the preferred embodiments ofa second surface spectral filter material as described herein. This willresult in the hue and/or chroma of the color of the perimeter of thedevice being more dependent on the second surface coatings than those onthe first surface. Nonetheless, especially when color is chosen near apoint of transition from perceived yellowish to bluish, +b* to −b*,respectively, or reddish to greenish, +a* to −a*, respectively, thesedifferences tend to become more perceivable. When attempting to matchthe hue of the spectral filter material to that of the overall field ofview of the reflector, small differences in the materials that result intransitions from more yellow to less yellow, or less blue to more blue,when compared to the overall field of view of the element may be avoidedby practicing the teachings herein. A similar contrast in reddish orgreenish hue may be managed.

For example, the color and reflectance of the ring and viewing area withand without a hydrophilic surface coating were modeled with a thin filmprogram. The spectral filter ring consists of 126 nm of ITO, 3 nm of Cr,5 nm of Rh, 30 nm of Ru and 40 nm of Cr. The exit medium or materialnext to the metals and dielectric layers is an electrochromic fluid withan index of approximately 1.365. The hydrophilic layer consists of a 65nm color suppression layer next to the glass, a 234 nm TiO2 layer with asurface morphology and 10 nm of SiO2.

Table 4a shows the reflectance and color of various portions of themirror. The first two rows show the effect of the presence or absence ofthe hydrophilic layer on the appearance of the ring. The color andreflectance are essentially unchanged with the application of thehydrophilic layer on the first surface of the mirror. In rows 3 and 4 wesee the change of color in the viewing area when the mirror is in thedarkened state. In the undarkened state the higher reflectance of theback reflector dominates the appearance. The reflectance increases withthe hydrophilic layer which may have advantages in certain markets. Thecolor of the viewing area without the hydrophilic layer in this case issomewhat objectionable because the thickness of the ITO is selected tooptimize the color of the ring. This results in a somewhat compromisedcolor in the viewing area. By adding the hydrophilic coating on surfaceone, the color becomes more neutral, a positive benefit to thecombination. The fifth row shows the color of the hydrophilic layerwithout any other coatings on surface two of the glass and with anelectrochromic fluid as the exit medium for reference.

TABLE 4a Color and reflectance of different mirror components StructureR a* b* Hydro/Glass/ITO/Cr/Rh/Ru/Cr 58.46 −4.20 3.23Glass/ITO/Cr/Rh/Ru/Cr 58.23 −4.20 1.96 Hydro/Glass/ITO 13.50 0.69 −3.10Glass/ITO 5.65 4.69 1.92 Hydro/Glass 12.47 −1.70 −4.60

Example Mirror Element Description

A particularly advantageous element configuration in conformance withFIGS. 17A-17C and 18 comprises a first substrate of glass approximately1.6 mm thick having a conductive electrode approximately 0.4 wavelengths(approximately 80 percent of half-wave) thick of indium-tin-oxideapplied over substantially the entire second surface by sputtering. Atleast a portion of the first corner, the edge and the second corner aretreated such that approximately 0.25 mm of material is removed from thesecond surface and approximately 0.5 mm of material is removed from thefirst surface. It should be apparent that a portion of conductiveelectrode is removed during treatment. A spectral filter materialapproximately 400 Å thick of chrome is applied approximately 4.5 mm widenear the perimeter of the first substrate proximate the conductiveelectrode. An electrical conduction stabilizing material approximately100 Å thick of a platinum group metal (PGM) (i.e., iridium, osmium,palladium, platinum, rhodium, and ruthenium) is applied approximately2.0 cm wide near the perimeter of the first substrate proximate thespectral filter material. A first separation area is laser etchedapproximately 0.025 mm wide with a portion thereof extending parallelto, and within the width of, a portion of a primary seal material areato substantially electrically insulate the first and second conductiveelectrode portions, spectral filter material portions and adhesionpromotion material portions. A second substrate of glass approximately1.6 mm thick having a conductive electrode approximately 0.5 wavelengthsthick over substantially all of the third surface is provided. A secondseparation area is laser etched approximately 0.025 mm wide with aportion thereof extending parallel to, and within the width of, aportion of a primary seal material to substantially electricallyinsulate the third and fourth conductive electrode portions. Areflective material approximately 400 Å thick of chrome is appliedproximate the third conductive electrode portion substantially definedby the inboard edge of the primary seal. An optional overcoatapproximately 120 Å thick of ruthenium is applied proximate thereflective material substantially defined by the inboard edge of theprimary seal. A primary seal material, comprising an epoxy having acycloaliphatic amine curing agent and approximately 155 μm substantiallyspherical glass balls, is provided to secure the first and secondsubstrates together in a spaced apart relation to define a chamber. Asubstantially rigid polymer matrix electro-optic medium, as taught inmany commonly assigned U.S. Pat. Nos. 5,679,283, 5,888,431, 5,928,572,5,940,201, 6,545,794, and 6,635,194, the disclosures which areincorporated in their entireties herein by reference, is providedbetween the first conductive electrode portion and the optional overcoatmaterial within the chamber through a plug opening in the primary sealmaterial. The plug opening is sealingly closed using ultra-violet lightcurable material with UV light irradiating the plug bottom through thethird and fourth surface. The cured primary seal material and the plugmaterial are inspected by viewing the element looking toward the fourthsurface. An electrically conductive material comprising a bisphenol Fepoxy functional resin, viscosity of approximately 4000 cP having acycloaliphatic amine curing agent, viscosity of approximately 60 cP, anda silver flake, tap density approximately 3 g/cc and average particlesize of approximately 9 μm is applied proximate the outboard edge of theprimary seal material between the second adhesion promotion materialportion, the third conductive electrode portion and the first electricalclip. This same electrically conductive material is applied proximatethe outboard edge of the primary seal material between the firstadhesion promotion material portion, the fourth conductive electrodeportion and the second electrical clip. A double sided, pressuresensitive, adhesive material is provided between the electrical clip andthe fourth surface of the second substrate. The electrically conductivematerial is cured after placement of the first and second electricalclips. The primary seal material is partially cured prior to applicationof the electrically conductive material; additional primary sealmaterial curing coincides with curing the electrically conductivematerial. This curing process is beneficial to prevent warping of theelement and improves overall related adhesion, sealing and conductivitycharacteristics.

This example mirror element description is provided for illustrativepurposes and in no way should be construed to limit the scope of thepresent invention. As described throughout this disclosure, there aremany variants for the individual components of a given element andassociated rearview mirror assembly.

In embodiments of the present invention having a highly reflectivespectral filter material applied between the second surface of the firstsubstrate and the primary seal, it has proven advantageous to usespecifically selected spacer material to eliminate bead distortion.Glass beads are typically added to the primary seal material to controlthe spacing between the substrates that form the chamber containing theelectro-optic medium. The diameter of preferably substantiallyspherically shaped glass beads is a function of the desired “cell”spacing.

These glass beads function well as spacers in electro-optic devices thathave two transparent substrates, a transparent front substrate and areflector positioned on surface three or four. These spacers alsofunction well in devices with a spectral filter material on the firstsurface or within the first substrate. However, when the spectral filtermaterial is applied proximate the primary seal material and the secondsurface, “dimples”, or small distortions in the chrome spectral filtermaterial, are created by typical glass spacer beads and are visible inthe seal area of a resulting mirror element. These dimples are alsovisible in mirror elements having a third surface reflector; however,they can only be seen if the mirror element is viewed looking at thefourth surface. These third surface dimples in a reflector are notvisible in a resulting mirror element when viewed once installed in avehicle.

In contrast, these dimples are readily visible in a resulting mirrorelement when the spectral filter material is proximate the secondsurface and covers the primary seal material area. These dimples arecreated, at least in part, by high stress areas proximate the glassspacer beads. Typically, the primary seal material comprises asubstantially rigid thermal curing epoxy; preferably comprising acycloaliphatic amine curing agent. The curing temperature of the epoxymaterial is often greater than 150 degrees Centigrade. There is often asignificant difference in thermal expansion between the customarily usedceramic glass bead (low coefficient of thermal expansion) and the epoxymaterial (high coefficient of thermal expansion). At least a portion ofthe glass spacer beads are in contact with the top material of arespective stack of materials proximate the second and third surfaces ofthe substrates when the seal solidifies and cures at high temperatures.As the mirror element cools in the post primary seal material curecycle, the seal material shrinks much more than the spacer beads andstress develops around the bead creating a distorted area, or dimple, inthe substrate stack. When the substrate comprises a reflector on asurface that is in contact with the primary seal material, thesedistorted areas or dimples are visually perceptible.

These distorted areas can be eliminated in a number of ways. A moreelastomeric or flexible primary seal material may be used thatinherently does not build areas of high stress. A spacer that is morecompressible may be used such that the spacer flexes as stress develops.A breakable spacer may also be used such that the spacer breaks torelieve the localized stress during primary seal material curing. A roomor low temperature curing seal material with low cure shrinkage may beused that will eliminate or minimize the thermal expansion-relatedstress. A seal material and spacers that are a closer match in thermalexpansion may be used to eliminate or minimize the thermalexpansion-related stress, such as plastic spacer beads and plastic sealmaterial, ceramic spacer beads and ceramic seal material or sealmaterial and/or spacer beads containing a thermal expansion modifyingfiller. The spacer beads in the seal material may be eliminatedaltogether if proper methods of element manufacturing are used tocontrol the element gap (“cell” spacing). For example, a spacing media,such as a PMMA bead or fiber that dissolves in the electro-optic media,could be applied to the area internal the primary seal to control theelement gap during primary seal material curing. The element substratesmay also be held apart mechanically until the seal solidifies.

Example 1 Primary Seal with Spacers

A master batch of thermal cure epoxy was made using 96 parts by weightDow 431 epoxy novolac resin, 4 parts fumed silica and 4 parts 2 ethyl 4methyl imidazole. To small portions of the above master batch 2 parts byweight of the following spacer materials were added. A dab of theepoxy/spacer mixture was then put on a 1″×2″×0.085″ thick piece ofchrome coated glass such that the epoxy mixture was in contact with thechrome reflector. A 1″×1″×0.85″ piece of ITO coated glass was placed ontop and the glass sandwich was clamped such that the glass piecesbottomed out to the spacer material. The element was then cured at about180 degrees Centigrade for about 15 minutes. Subsequently, once theelement returned to room temperature, it was visually inspected fordimples looking at the chrome as if it were on surface two.

Example 2 Primary Seal Material

Using the thermal cure epoxy of Example 1 with 140 um glass beads causeda very heavy dimple pattern to be visible.

Example 3 Primary Seal Material

Using the thermal cure epoxy of Example 1 with plastic beads(Techpolymer, Grade XX-264-Z, 180 um mean particle size, SekisuiPlastics Co. Ltd., Tokyo, Japan) caused no dimple pattern to be visible.

Example 4 Primary Seal Material

Using the thermal cure epoxy of Example 1 with plastic fibers (Trilene,140 um diameter monofilament line cut to 450 um lengths, Berkley, SpringLake, Iowa) caused no dimple pattern to be visible.

Example 5 Primary Seal Material

Using the thermal cure epoxy of Example 1 with hollow ceramic beads(Envirospheres, 165 um mean particle size, Envirospheres PTY Ltd.,Lindfield, Australia) caused very slight, but acceptable, dimple patternto be visible.

Example 6 Primary Seal Material

Using an epoxy cured at room temperature caused no dimple pattern to bevisible after 1 week at room temperature.

Example 7 Primary Seal Material

Using two parts by weight glass beads (140 um) added to a UV curableadhesive, Dymax 628 from Dymax Corporation, Torrington, Conn., andcompressing the adhesive between two glass substrates as described abovecaused a very slight, but acceptable, dimple pattern to be visible. Theadhesive was UV cured at room temperature.

Turning now to FIG. 20A, a cross sectional view of an embodiment of anelectro-optic mirror element 545 is depicted to include a light source2030 mounted to a circuit board 2031 positioned such that light raysemitted by the light source 2030 are transmitted through the element 545to a viewer (not shown) observing the first surface 612 a. In apreferred embodiment of the electro-optical mirror element of theinvention, where high dimming/clearing speeds and/or short electricalcontacts are desired, the substantially transparent layer 628 (which inan alternative embodiment may comprise multiple layers, such as, e.g.,layers 628 a and 628 b as shown) on the second surface must have highconductivity (which corresponds to a low sheet resistance). Therefore,the sheet resistance of the electrode layer 628 a (or layers 628 a,b) ispreferably chosen to be between approximately 1 Ω/square andapproximately 10 Ω/square, preferably between approximately 2 Ω/squareand approximately 6 Ω/square, and most preferably approximately 3Ω/square. Typically ½ wave ITO or full wave SnO(F) with a sheetresistance of 10 to 15 Ω/square is used on the second surface inelectro-optic mirrors made today. Such low sheet resistance can beachieved by providing thicker layers of conventional materials such asITO, tin-oxide, zinc-oxide, or combinations thereof. If the opticalthickness of the coatings is two waves or greater, there are alsobenefits in the color intensity and color variation that is contributedto the low end reflectance of the associated mirror element whencompared to thinner coatings that are not color suppressed thickerlayers, approximately two wave or above, provide benefits with regard tomanufacturing variances. Other suitable low sheet resistancesubstantially transparent conductors can be made by combining layers ofconductive metal oxides with metals or metal alloys. These stacks may beITO/silver/ITO or ITO/silver alloy/ITO or may be stacks such as thoseused as low E coatings in the IG industries such as ZnO/Ag/ZnO/Ag/ZnO.Unlike low E-coatings for windows, to be useful in an electrochromicdevice, the conductivity interlayer should be continuous and theconductivity must reach the surface. To improve interlayer conductivity,dopants may be added such as aluminum or gallium. These dopants enhancethe conductivity of the zinc oxide layers. To prevent the oxidation ofthe metal or metal alloy, thin layers of a protective metal such astitanium or zinc can be applied during the deposition process. Theembodiment 2000 shown in FIG. 20 comprises a four layer stack coating2020 b, 2020 c, 2020 d, 2020 e applied to the third surface 614 a of thesecond substrate 614. A layer of opaque material 2015 is applied to thefourth surface 614 b with a cut-out for the light from the light source2030 to be projected through. Many alternate coatings and reflective,transflective and substantially transparent layers are disclosed invarious U.S. patents and U.S. patent applications incorporated herein byreference. It should be understood that a lower sheet resistance coatingmay be provided in an area proximate the associated electrical contactor around a perimeter area and allow the sheet resistance to increase asthe distance from the electrical contact increases; this is particularlyapplicable when point contacts are utilized.

Turning now to FIG. 20B, a cross sectional view of an embodiment of anmirror element is shown to include the first substantially transparentsubstrate 612 in a spaced-apart relationship to the second substrate 614with the seal member 616 therebetween. The substantially transparentelectrically conductive layer 628 is applied to the second surface 612 band the reflective electrode layer 628 is applied to the third surface114 a. Preferably, the substantially opaque material 1676 is applied tothe first surface 612 a substantially circumferentially (i.e.,configured as a ring) in a peripheral area of the first surface suchthat ambient light incident through the first surface 612 a is preventedfrom impinging upon the seal member 616. Electrical contacts 2080, 2082are provided to facilitate electrical connection to the electricallyconductive layers on the third and second surfaces, respectively. In apreferred embodiment, the substantially opaque material 1676 has areflectivity substantially equivalent to that of the reflectiveelectrode layer 620 disposed on the third surface. In an alternativeembodiment, the substantially opaque material 1676 may be transmissiveto all wavelengths of light except those in the ultra-violate and/or theinfrared region(s) of the spectrum, while the seal material 616 issubstantially transparent. In another alternative embodiment, thesubstantially opaque material 1676 may be provided on the second surface112 b (not shown) in lieu of the first surface 112 a or it may beembedded in the first substrate. The use of such substantially opaquematerial 1676 applied to the perimeter of a mirror on the first surfaceor the second surface of the front substrate 612 the edge of which hasbeen properly treated may allow for production of an EC-mirror assemblythat requires no bezel or a bezel with a vary narrow lip. Materials suchas, for instance, chrome, molybdenum, stainless steel, nickel ortitanium applied can be chosen to form the element 1676. The chosenmaterial needs to exhibit good adhesion to glass or to coatings on theglass, and if used on surface one, good abrasion resistance and goodenvironmental stability (water, salt, etc.). It is also desirable tohave the ring of material 1676 closely match the color and reflectivityof the interior of the EC-mirror system. If the EC mirror proper has areflectivity between around 50% to 70%, a front surface chrome perimetercoating 1676 matches well. If the EC-mirror system has a reflectivitygreater than 70%, it may be necessary to increase the reflectivity ofthe perimeter ring. The latter can be done without compromising theabrasion resistance and chemical durability by making the ring out ofhighly reflective hard metals (hardness of 5 mhos or above) such asmetals from the platinum metals group that includes rhodium, platinumand ruthenium. Because these metals do not adhere well to glass or glasslike metal oxide coatings it is preferred that these highly reflectivemetals are put over a layer such as chrome that has good glass adhesion.Therefore a combination such as a base layer of chrome, molybdenum ornickel over coated with a hard high reflectance material such asrhodium, ruthenium or platinum will adhere well to glass like materials,resist abrasion and have good environmental durability. If a ring withlow reflectivity that is dark or black is desired a coating of materialssuch as “black chrome” or oxides of Cr, Cu, Mn, Mo, and Fe or theircombinations can be used. A ring that is a particular color can be madein a similar fashion.

FIGS. 21A and 21B depict plan views of mirror elements havingsubstantially zero positional offset between the front substrate 612 andthe rear substrate 614 except for in the tab/recess areas 2134, 2135where contact is made to corresponding second and third surfaceconductive layers (not shown). The first and second substrates aresecured in spaced apart relationship with one another via seal member616. The substantially opaque material 1676 is provided as describedwith reference to FIG. 20B.

In a preferred embodiment, low sheet resistance stacks, as describedherein, are provided on both the second and third surface such thatrelatively short electrical contacts, leading to the electricallyconductive layers on the second and third surfaces, are sufficient. Inat least one preferred embodiment, the length of the contacts to thesecond and third surfaces combined are less than approximately 50percent, and preferably less than approximately 25 percent, of thelength of the perimeter of the associated mirror element. In at leastone alternate embodiment, a point contact is provided to either thesecond surface conductive layer, the third surface conductive layer orboth the second and third surface conductive layers. In at least oneembodiment, the contact to the second electrically conductive layer isapproximately 60 to approximately 75 percent of the total length of bothcontacts combined. In at least one embodiment anyone of these, “shortelectrical contact” systems may be combined with a carrier withintegrated bezel as described herein with regard to FIGS. 60 and 61.Optionally, a substantially transparent seal member and, or, asubstantially opaque material may be provided, as described herein, incombination with the short electrical contact(s). U.S. Pat. No.5,923,457, the entire disclosure of which is incorporated herein byreference, discloses optional structures for mirror elements inaccordance with various embodiments of the present invention.

Edge Treatment.

If any coating and/or a reflective peripheral ring of material isapplied around the perimeter of the mirror on the first or secondsurface to mask the seal and/or contact areas, as discussed in referenceto FIGS. 20A, 20B, 21A, 21B and other embodiments described herein, theaesthetics of this ring and edge of the ring become very important.Appearance of the edge of the first substrate plays a special role inassuring that the user's perception of the mirror is satisfying.Following the practical consideration and the trends in users'preferences in appearance of the vehicular rearview assemblies, the edgeof the first substrate should be configured to be optically diffusivefor at least two reasons.

1) In majority of cases, glass substrates of a mirror element of arearview assembly are produced through scribing and breaking processthat generally results in a reflective perimeter edge having specularreflective properties and reflecting about 4 percent of the incidentlight. (It is understood that this reflectivity level is inevitablyincreased if the specularly reflecting edge is overcoated with aperipheral ring of material such as Chrome.) The smooth specularreflective edge can give a bright or shiny appearance to the glass edgein many ambient light conditions, which is generally aestheticallyobjectionable.

1) Moreover, if the edge of a mirror element is chipped or cracked andis overcoated with a reflective peripheral ring of spectral filtermaterial (such as chromium, for example), the chipping becomes extremelyvisible and stands out like a beacon scattering incident light in alldifferent directions. This shortcoming becomes particularly aggravatedif a chip or a crack extends onto the perimeter of the first or secondsurface. Similarly, if the perimeter and/or edge is chipped after thechrome peripheral ring coating is applied, the chip visually stands outin reflected light as a dark void on otherwise a smooth bright surface.

It is appreciated that both the specularly reflecting edge andimperfections associated with chipping of the edge of the mirror elementbecome especially problematic in embodiments having either a narrowbezel or no bezel at all, because in such embodiments the chipping arenot concealed. At least for the reasons discussed above it is preferred,therefore, to configure the first substrate so as to improve both themechanical quality and the visual appearance of the edge of the mirrorelement in order to produce a high quality mirror. Both of these goalsmay be achieved by modifying the surface properties of the edge of thefirst substrate. Required modifications are produced, for example, byre-shaping the edge either after the coating has been applied to theedge or, preferably, right after the mirror substrates are cut to shape.Re-shaping may be performed by grinding, sanding, or seaming the edgewith flat or contoured wheels containing abrasive particles or with amoving belt coated with abrasive particles. Depending on a configurationof the carrier and whether or not a bezel component extends onto thefirst surface of the mirror element, a light edge treatment that removesas little as 0.005″—or as much as 0.010″ to 0.075″—of the front edge ofthe first may be all that is necessary to achieve a desired result.

Abrasive materials include but are not limited to diamond, siliconcarbide or oxides of aluminum, cerium, zirconium and iron in the sizerange of about 100 to 1200 mesh. The size of the particles used affectsthe roughness of the finished glass edge. The larger the abrasiveparticle the rougher the surface that is created. Generally 80 to 120mesh size abrasive particles produce a very rough surface, 300 to 500mesh size particles produce a smooth surface and 600 mesh and aboveproduce a near polished finish. The abrasive particles can be embeddedin a metal, resin or rubber medium. An example of abrasives loaded inmetal or resin binder are diamond wheels available from GlassLine Corp.,28905 Glenwood Rd., Perrysburg, Ohio 43551 or Salem Corp., 5901 Gun ClubRd., Winston-Salem, N.C. 27103. An example of abrasives loaded in arubber binder are Cratex M or Cratex F wheels available fromCratex/Brightboy Abrasives Co., 328 Encinitas Blvd. Suite 200,Encinitas, Calif. 92024. Abrasive coated belts are available from 3MCorp., St. Paul, Minn. 55144. Modification of the surface properties ofthe edge not only increases the mechanical durability of the edge byremoving the micro-cracks but also makes the edge optically diffusive.The re-shaping is generally done in the presence of a coolant to removethe heat generated during grinding or seaming. The edge can also bereshaped by rubbing the glass against a substrate flooded with anabrasive slurry loaded with particles such as diamond, silicon carbideor oxides of aluminum, cerium, zirconium and iron. Equipment for edgepolishing using the abrasive slurry method is available from SpeedFamCo., Kanagawa, Japan. Alternatively, the edge can be reshaped by cuttingor blasting the edge with a high pressure liquid containing abrasiveparticles of diamond, silicon carbide or oxides of aluminum, cerium,zirconium and iron. Equipment for frosting glass using this method isavailable from Bystronic, 185 Commerce Dr., Hauppauge, N.Y. 11788.Alternative way of reshaping the edge may include blasting the edge withabrasive particles of diamond, silicon carbide or oxides of aluminum,cerium, zirconium and iron carried by a high velocity gas stream. Amodified glass edge can also be produced by chemically etching the glasswith a chemical solution designed to leave a frosty surface such asSuperfine Glass Frosting Powder which a mixture of ammonium hydrogenfluoride and barium sulfate that is mixed with HCl available from AboveGlass Corp., 18341 4^(th) Ct., Miami, Fla. 33179. A modified glass edgecan also be produced by coating the glass edge with a diffuse orpigmented paint such as 935 UV Series available from Ruco, Wood Dale,Ill. or UV 420 Series available from Fluorital Italy, Italy orUltraglass UVGO Series available from Marabu, Germany or Crystal GLSSeries available from Sun Chemical, Parsippany, N.J. or SpecTruLite UVSeries available from Ferro Corp., Cleveland, Ohio.

Turning now to FIG. 21C, an embodiment of a mirror element is shown tohave the first substrate 612 that is larger than the second substrate614 such that an electrical contact to the second and third surfaceelectrically conductive layers (not shown) is made inside the perimeterof the first substrate and is not visible when the element is viewedfrom the front of the mirror element. A seal member 616, and optionally,a substantially opaque material 1676 is provided as described withregard to other embodiments. It should be understood that alternateembodiments may be provided with a front substrate that is in positionalalignment with the rear substrate on all put one edge and that contactto the second and third surface electrically conductive layer(s) is madeon the edge having the extended front substrate. In addition to the “J”and “C” type electrical contact clips described and depicted below, a“Z” type contact clip may be provided (which is especially useful in anembodiment having a larger first substrate). The Z-type clip has aportion of one end secured to the second surface of the front substratewhere the front substrate extends beyond the rear substrate, the Z clipthen steps up along the edge of the rear substrate and the opposing endof the Z clip then extends along the fourth surface. In at least oneembodiment, a Z clip is provided to make contact to the second surfaceand a J or C clip is employed to make contact to the third surface. Forembodiments with larger, wide, clips that are bonded to the substrate,the thermal coefficient of expansion of the clip(s) and the thermalcoefficient of the substrate are substantially matched, for example, ifthe substrate is glass, a Kovar, stainless steel or a laminate ofMo/Cu/Mo clip may be employed.

Additional Embodiments of Electrical Connectors.

FIG. 22A illustrates one technique for providing for electrical couplingto an electrochromic device such as that of the first embodiment. Asshown, a first electrically conductive clip 2280 is clipped to element614 so as to be in electrical contact with second portion 620 b ofelectrode 620. A second electrically conductive clip 2282 is providedthat clips around the entire device and thus contacts front surface 612a of front element 612 and rear surface 614 b of rear element 614.Electrical contact is made to electrode 628 via first portion 620 a ofelectrode 620, and via electrically conductive material 852. A variationof this construction is shown in FIG. 22B in which 2282 is made of anidentical construction as that of clip 2280 so as to clip only to rearelement 614. Again, electrical coupling between clip 2282 and electrode628 is through electrically conductive seal 852 and any wire 850 thatmay be disposed therein. As shown in FIG. 22C, one or a plurality ofsuch clips may be provided for electrical connection to each electrode620 or 628. Clips 2280 and 2282 may be directly soldered or otherwiseconnected to a circuit board or wires extending therebetween may besoldered to clips 2280 and 2282. FIGS. 22D and 22E show two additionalvariants of the clips 2280 and 2282 discussed above. In FIG. 22D, clips2280 a and 2282 a are modified such that they do not extend around rearsurface 614 b of rear element 614. In FIG. 22E, clips 2280 b and 282 bare modified so as to extend over and around front surface 612 a offront element 612 while also extending around rear surface 614 b of rearelement 614. As will be apparent to those skilled in the art, variousmodifications can be made to the disclosed clip designs withoutdeparting from the scope of the present invention.

FIG. 23 shows a variation of the embodiment shown in FIG. 13 describedabove. The structure shown in FIG. 23 differs in that one of the layersof conductive foil or web 1366 extends outward beyond the edges ofelements 612 and 614 and wraps around element 614 for connection toeither a printed circuit board or a heater circuit. Additionally, therear surface 614 b of rear element 614 may be patterned with conductiveelectrodes for supplying power to foil 1366. The foil 1366 on theopposite side of insulator 1364 may likewise extend outward forconnection to the other of electrodes 628 and 620. Foil 1366 may be cutusing pinking shears and effectively bent to form one or more connectorclips. Foil 1366 may be configured as an electrical bus with tabsextending into the seal.

FIG. 24 shows yet another embodiment in which a conductive coating 2390is deposited on the peripheral edge of rear element 614. Such a coatingmay be made of metal and applied with solder. Alternatively, thematerial may be rolled onto the edge of element 614. Such a constructionallows contact merely to the edges of element 614 to provide electricalcoupling to one or both of electrodes 620 and 628.

Yet another embodiment is shown in FIG. 25. In this embodiment, themajority of the sealing member is moved from between the front and rearelements 612 and 614 to the edge of the front and rear elements. Thus,the seal is provided predominately on the peripheral edges of the frontand rear elements. As shown in FIG. 25, the seal 2500 contacts the frontelement 612 both on the peripheral edge and the rear surface of thefront element. Likewise, the seal 2500 contacts the rear element 614both on the peripheral edge and the front surface of the rear element. Afirst contact area in which seal 2500 contacts the peripheral edge offront element 612 is larger than a second contact area in which seal2500 contacts the rear surface of front element 612. Likewise, a thirdcontact area in which seal 2500 contacts the peripheral edge of rearelement 614 is larger than a fourth contact area in which seal 2600contacts the front surface of rear element 614. As a result, aninterface between seal 2600 and front element 612 defines an oxygenpenetration path length through which oxygen would have to travel toenter chamber 626, wherein the portion of the path length extendingalong the peripheral edge of front element 612 is longer than theportion of the path length extending along the rear surface of frontelement 612. Similarly, an interface between seal 2500 and rear element614 defines another oxygen penetration path length through which oxygenwould have to travel to enter chamber 626 wherein the portion of thispath length extending along the peripheral edge of rear element 614 islonger than the portion of the path length extending along the frontsurface of rear element 614. By forming seal 2500 of a thin member 2502of a first material having an oxygen permeability of less than 2.0cm³·mm/m²·day·atm and/or by increasing the oxygen penetration pathlength as compared to other electrochromic cells, the amount of oxygenpenetration into chamber 626 may be significantly reduced. Typical priorart seals are made of epoxy resins, which have oxygen permeabilities of2.0-3.9 cm³·mm/m²·day·atm and water permeabilities of 0.7-0.94gm·mm/m²·day, and are predominately positioned between the front andrear elements thereby having a shorter oxygen penetration path length.

First material forming thin member 2502 may be made of a materialselected from the group of: metal, metal alloy, plastic, glass, andcombinations thereof. First material 2502 is adhered to the peripheraledges of the front and rear elements with a second material 2504. Thesecond material may have a higher oxygen permeability than said firstmaterial, and may be an electrically conductive adhesive or anelectrically conductive epoxy that makes electrical contact with atleast one of first and second electrically conductive layers 620 and628.

In the preferred embodiment of the invention, the sealing member 2500includes a thin member 2502 with low gas permeability that is adhered tothe edge of the front and rear elements. An adhesive 2504 such as anepoxy adhesive, PSA or hot melt can be applied in a thin film to a thinmember 2502 with low gas permeability such as a metal foil or plasticfilm. Examples of materials that may be used as thin member 2502 includepolycarbonate (oxygen permeability of 90.6-124 cm³·mm/m²·day·atm andwater permeability of 3.82-4.33 gm·mm/m²·day), polyvinylidene chloride(oxygen permeability of 0.0152-0.2533 cm³·mm/m²·day·atm and waterpermeability of 0.01-0.08 gm·mm/m²·day), and a multilayer film ofplastic and/or metal. Such a film may include inorganic layers or acoating such as SiO₂, Al₂O₃, Ta₂O₅, Al, chrome, etc. that is bonded tothe edges of the front and rear glass elements with an adhesive or glassfrit. An example of a suitable multilayer film is the SARANEX brandPE/PVC-PVDC film, which has an oxygen permeability of 0.2-0.79cm³·mm/m²·day·atm and water permeability of 0.06-0.16 gm·mm/m²·day.

This foil or film 2502 is then wrapped around the front and rearsubstrates that are held in the proper spaced apart relationship. Theadhesive 2504 bonds the foil or film 2502 primarily to the substrateedges to form a gas and liquid tight seal around the perimeter of theelectrochromic device. A fill port 2606 (FIG. 26) could be added byleaving a gap in the foil or film edge sealing member or punching a holethrough it. The fill hole could be soldered shut if a metal foil is usedfor the edge-sealing member. Alternatively, the fill hole could beplugged with an UV or visible light curing adhesive or hot melt or anadditional thin sealing member such as a foil or film could be gluedover the fill hole. If a light transparent film is used, a UV or visiblelight curing adhesive could be used to adhere the film. If anon-transparent metal foil is used a hot melt, PSA or other self-curingadhesive can be used. In this way the area that is required for a sealthat is primarily between the substrates is eliminated and a bezel thathad been designed to cover that area can be made narrower or eliminated.

If the low gas permeability member adhered to the side of the substrateshas areas that are electrically conductive this member could also serveas an electrical bus to make contact to the conductive electrodes of theelectrochromic device. Electrical isolation of the electrodes could bemaintained by creating gaps in the electrical continuity of the edgeseal member. For example, if a metal foil was used, small slits or gaps2606 (FIG. 26) could be created in the foil such as one to be used as afill hole and another opposite the fill hole to electrically isolate topand bottom electrode buses. Electrical continuity between the conductiveedge sealing member and the electrode could be established in any numberof ways. The conductive electrode coating(s) 620 and/or 628 could wraparound the side of the substrate(s) (FIGS. 27 and 28) or an electricallyconductive coating or adhesive 3008 (FIG. 30A-33) could be applied inareas that electrical connection to the edge bus is desired. Theconductive sealing member 2502 could have a dimple or crease 2710 (FIG.27) or include an inward protruding extension 2914 (FIG. 29) to makecontact through the adhesive bonding of the sealing member to the sideof the substrate to make contact to the electrode coating or edgecoating 620,628. Conductive particles in the adhesive or a conductiveadhesive 3008 could be used to make electrical contact between theconductive edge sealing member and the electrode coating or edgecoating. A wire (2812 in FIG. 28), metal clip (3416 in FIG. 34) or otherconductor could then be used to make contact between the electricallyconductive edge seal 2502 and the electrochromic device driveelectronics. An electrochromic device made in this manor would requirelittle or no bezel to cover the seal and contact area. A more detaileddiscussion of FIGS. 30A-34, is provided below.

As shown in FIGS. 30(A, B), thin seal member 2502 may be secured to theperipheral edges of elements 612 and 614 using both an electricallyconductive material 3008 and a nonconductive material 2504. As depictedin FIG. 30A, the conductive material 3008 provides an electricalconnection from conductive layer 628 to a first portion 2502 a (see FIG.26) of seal member 2502. As depicted in FIG. 30B, the conductivematerial 3008 provides an electrical connection from conductive layer620 to a second portion 2502 b of seal member 2502. As mentioned above,fill ports, gaps or slits in the thin seal member and conductivematerial 3008 may be used to electrically isolate portions 2502 a and2502 b of thin seal member 2502.

In the embodiment shown in FIG. 31, conductive layers 628 and 620 areconfigured and oriented as shown in FIG. 10C, such that the conductivematerial 3008 provides an electrical connection from conductive layer628 to a first portion 2502 a (see FIG. 26) of seal member 2502, and theconductive material 3008 also provides an electrical connection fromconductive layer 620 to a second portion 2502 b of seal member 2502. Asmentioned above, fill ports, gaps or slits in the thin seal member andconductive material 3008 may be used to electrically isolate portions2502 a and 2502 b of thin seal member 2502.

FIG. 32 shows an embodiment similar to FIG. 31 with the exception thatregions 628 a and 620 a of conductive layers 120 and 628 are eliminated.

FIG. 33 shows an embodiment wherein only the center portion of theadhesive material disposed between layers 620 and 628 is electricallyconductive, while nonconductive is used to adhere seal member 2502 tothe peripheral edges of elements 612 and 614. This provides theadvantage that electrically conductive material 3008 may not need to beas effective as an adhesive with respect to thin member 2502.

FIG. 34 shows an embodiment wherein a clip 3416 (similar to clip 2282 inFIGS. 22B and 22C) used in combination with thin seal member 2502, whichmay be a metal foil or the like. As illustrated, a solder bump 3420 maybe provided for soldering thin foil 2502 to clip 3416.

Electrical Communication with the Back of the Mirror System.

As follows from the description of the embodiment shown in FIG. 18, theelectrically conductive material (e.g., 1848) may be in electricalcontact with either of the second and third surface conductive electrodeportions. Turning to FIGS. 35(A-N), there are shown various options forselectively contacting a particular portion of the second and thirdsurface conductive electrode portions 3505, 3510.

The element construction depicted in FIG. 35(A) comprises a firstsubstrate 3502 a having a second surface stack of materials 3508 a and asecond substrate 3512 a having a third surface stack of materials 3522a. The third surface stack of materials is shown to have an isolationarea 3583 a such that a portion of the third surface stack of materialsthat is in contact with a conductive epoxy 3548 a is isolated from theremainder of the third surface stack of materials. The first and secondsubstrates are held in spaced-apart relationship to one another via aprimary seal material 3578 a. It should be understood that another sideof the element may have a similar isolation area associated with thesecond surface stack of materials for providing contact to the thirdsurface stack of materials within the viewing area. It should beunderstood that either the second or third surface stack of materialsmay be a single layer of on materials as described elsewhere herein andwithin references incorporated herein by reference.

The element construction depicted in FIG. 35(B) comprises a firstsubstrate 3502 b having a second surface stack of materials 3508 b and asecond substrate 3512 b having a third surface stack of materials 3522b. The first and second substrates are held in a spaced-apartrelationship with respect to one another via a primary seal material3578 b. An electrically conductive epoxy 3548 b is in contact with thethird surface stack of materials and electrically insulated from thesecond surface stack of materials via the insulating material 3583 b. Itshould be understood that another side of the element may have a similarisolation area associated with the second surface stack of materials forproviding contact to the third surface stack of materials within theviewing area. It should be understood that either the second or thirdsurface stack of materials may be a single layer of on materials asdescribed elsewhere herein and within references incorporated herein byreference.

The element of FIG. 35(C) comprises a first substrate 3502 c having asecond surface stack of materials 3508 c and a second substrate 3512 chaving a third surface stack of materials 3522 c. The first and secondsubstrates are held in spaced apart relationship with respect to oneanother via a primary seal material 3578 c. The second surface stack ofmaterials extends toward the edge of the first substrate beyond theprimary seal material such that it is in electrical contact with a firstelectrically conductive epoxy, or first solder, 3548 c 1. The thirdsurface stack of materials extends toward the edge of the secondsubstrate beyond the primary seal material such that it is in electricalcontact with a second electrically conductive epoxy, or second solder,3548 c 2. It should be understood that another side of the element mayhave a similar isolation area associated with the second surface stackof materials for providing contact to the third surface stack ofmaterials within the viewing area. It should be understood that eitherthe second or third surface stack of materials may be a single layer ofon materials as described elsewhere herein and within referencesincorporated herein by reference.

FIG. 35(D) depicts the second surface electrical contact 3548 d 1 beingmade on an opposite side of the element from a third surface electricalcontact 3548 d 2. FIG. 35(E) depicts the second surface electricalcontact 3548 e 1 being made on a side of the element and the thirdsurface electrical contact being made on an end of the element. FIG.35(F) depicts the second surface electrical contact 3548 f 1 being madeon one side and continuously with one end of the element and the thirdsurface electrical contact 3548 f 2 being made on an opposite side andcontinuously with an opposite end of the element. FIG. 35(G) depicts thesecond surface electrical contact 3548 g 1 being made on opposite sidesof the element and the third surface electrical contact 3548 g 2 beingmade on an end of the element. FIG. 35(H) depicts the second surfaceelectrical contact 3548 h 1 being made on opposite sides of the elementand the third surface electrical contact 3548 h 2 being made on oppositeends of the element. FIG. 35(I) depicts the second surface electricalcontact 3548 i 1 being made continuously on opposite ends and one sideof the element and the third surface electrical contact 3548 i 2 beingmade on one side of the element. It should be understood that, in atleast one embodiment, the longer electrical contact will correspond tothe surface having the highest sheet resistance stack of materials. Itshould be understood that the electrical contact may be via electricalconductive epoxy, solder or an electrically conductive adhesive.

FIG. 35(J) depicts an element comprising a first substrate 3502 j havinga second surface stack of materials 3508 j and a second substrate 3512 jhaving a third surface stack of materials 3522 j. The first and secondsubstrates are held in spaced apart relationship with respect to oneanother via perimeter first and second primary seals 3548 j 1, 3548 j 2.The first primary seal functions to make electrical contact with thesecond surface stack of materials and the second primary seal functionsto make electrical contact with the third surface stack of materials.The first and second primary seals hold the first and second substratesin a spaced apart relationship with respect to one another andpreferably both primary seals are substantially outside the edge of eachsubstrate.

With reference to FIG. 35(K), a profile view of a portion of a rearviewmirror element is depicted comprising a first substrate 3502 k having atleast one layer 3508 k of a substantially transparent conductivematerial deposited on the second surface and a second substrate 3512 khaving a stack of materials deposited on the third surface secured in aspaced apart relationship with respect to one another via a primary sealmaterial 3578 k to define a chamber there between. In at least oneembodiment, an electro-optic medium 3510 k is located within saidchamber. In at least one embodiment, the third surface stack ofmaterials comprises an underlayer 3518 k, a conductive electrode layer3520 k, a metallic layer 3522 k and a conductive tab portion 3582 khaving an overlap portion 3583 k underneath the metallic layer andprimary seal material. It should be noted that the conductive tabportion 3582 k could alternatively be deposited over the metalliccoating 3522 k to create the overlap portion. In at least oneembodiment, the underlayer is titanium-dioxide. In at least oneembodiment, the underlayer is not used. In at least one embodiment, theconductive electrode layer is indium-tin-oxide. In at least oneembodiment, the conductive electrode layer is omitted. In at least oneembodiment, the conductive electrode layer emitted and the underlayer iseither a thicker layer of titanium-dioxide or some other substantiallytransparent material having a relatively high index of refraction (i.e.,higher index of refraction than ITO), such as, silicon carbide. In atleast one embodiment, the conductive tab portion comprises chrome. Itshould be understood that the conductive tab portion may comprise anyconductive material that adheres well to glass and is resistant tocorrosion under vehicular mirror testing conditions. As can beappreciated, when the third surface stack of materials, or at leastthose layers within the stack that are susceptible to corrosion, arekept within an area defined by an outer edge of the primary sealmaterial, the element will be substantially immune to problemsassociated with third surface corrosion. It should be understood thatthe layer, or layers, susceptible to corrosion may extend beyond theprimary seal material provided a protective overcoat or sealant isincorporated, such as, conductive epoxy or an overcoat layer. It shouldbe understood that any of the first, second, third and fourth surfacelayers or stacks of materials may be as disclosed herein or within thereferences incorporated elsewhere herein by reference. It should beunderstood that the conductive tab portion improves conductivity overthe conductive electrode; as long as a conductive electrode layer isprovided with sufficient conductivity, the conductive tab portion isoptional. In at least one embodiment, the conductive electrode layerimparts the desired color specific characteristics of the correspondingreflected light rays in addition to providing the desired conductivity.Therefore, when the conductive electrode is omitted, colorcharacteristics are controlled via the underlayer materialspecifications.

Turning to FIG. 35(L), a profile view of a portion of a rearview mirrorelement is depicted comprising a first substrate 3502 l having at leastone layer 3508 l of a substantially transparent conductive materialdeposited on the second surface and a second substrate 3512 l having astack of materials deposited on the third surface secured in a spacedapart relationship with respect to one another via a primary sealmaterial 3578 l to define a chamber there between. In at least oneembodiment, an electro-optic medium 3510 l is located within saidchamber. In at least one embodiment, the third surface stack ofmaterials comprises an underlayer 3518 l, a conductive electrode layer3520 l, a metallic layer 3522 l and a conductive tab portion underneaththe primary seal material. In at least one embodiment, a void area 3583l is defined between the metallic layer and the conductive tab portion,the conductive electrode provides electrical continuity there between.In at least one embodiment, the underlayer is titanium-dioxide. In atleast one embodiment, the underlayer is not used. In at least oneembodiment, the conductive electrode layer is indium-tin-oxide. In atleast one embodiment, the conductive tab portion comprises chrome. Itshould be understood that the conductive tab portion may comprise anyconductive material that adheres well to glass and is resistant tocorrosion under vehicular mirror testing conditions. As can beappreciated, when the third surface stack of materials, or at leastthose layers within the stack that are susceptible to corrosion, arekept within an area defined by an outer edge of the primary sealmaterial, the element will be substantially immune to problemsassociated with third surface corrosion. It should be understood thatany of the first, second, third and fourth surface layers or stacks ofmaterials may be as disclosed herein or within the referencesincorporated elsewhere herein by reference.

With reference to FIG. 35(M), a profile view of a portion of a rearviewmirror element is depicted comprising a first substrate 3502 m having atleast one layer 3508 m of a substantially transparent conductivematerial deposited on the second surface and a second substrate 3512 mhaving a stack of materials deposited on the third surface secured in aspaced apart relationship with respect to one another via a primary sealmaterial 3578 m to define a chamber there between. In at least oneembodiment, an electro-optic medium 3510 m is located within saidchamber. In at least one embodiment, a first metallic layer 3518 m isdeposited over substantially the entire third surface. In at least oneembodiment, a second metallic layer 3520 m is deposited over the firstmetallic layer such that an outer edge of the second metallic layer islocated within an area defined by an outer edge of a primary sealmaterial 3578 m. In at least one embodiment, the first metallic layercomprises chrome. In at least one embodiment, the second metallic layercomprises silver or a silver alloy. It should be understood that any ofthe first, second, third and fourth surface layers or stacks ofmaterials may be as disclosed herein or within the referencesincorporated elsewhere herein by reference.

Turning to FIG. 35(N), a second substrate 3512 n is depicted comprisinga stack of materials having an eyehole 3522 n 1 substantially in frontof a light sensor or information display. In at least one embodiment, afirst metallic layer 3518 n is provided with a void area in the eyeholearea. In at least one embodiment, a second metallic layer 3520 n isprovided with a void area in the eyehole area. In at least oneembodiment, a third metallic layer 3522 n is provided. In at least oneembodiment, only the third metallic layer is deposited in the eyeholearea. In at least one embodiment, the first metallic layer compriseschrome. In at least one embodiment, the second metallic layer comprisessilver or silver alloy. In at least one embodiment, the third metalliclayer comprises a thin silver, chrome or silver alloy. It should beunderstood that any of the first, second, third and fourth surfacelayers or stacks of materials may be as disclosed herein or within thereferences incorporated elsewhere herein by reference.

One way the spectral filter material 3515, proximate a first surfaceconductive electrode, can be electrically insulated from otherconductive electrode portions is by overcoating at least portions of thespectral filter material with an organic or inorganic insulatingmaterial as depicted in FIG. 35(B).

When a spectral filter material, such as chrome metal, is applied on topof the transparent conductor of the second surface through a mask in acoating operation (e.g., by vacuum sputtering or evaporation), anon-conductive coating may be applied through a mask in the same processto electrically isolate the second surface conductive electrode from thethird surface conductive electrode in the conductive seal area.

Example 1 Insulating Material

A spectral filter material comprising metal, metal alloy, layers ofmetals, layers of metal alloys or combinations thereof, such as chrome,molybdenum, stainless steel, or aluminum, rhodium, platinum, palladium,silver/gold, white gold and ruthenium, often over an adhesion promotionmaterial such as chrome, is vacuum deposited through a mask over atransparent conductor (such as ITO) to cover the seal area. Aninsulating material such as silicon, silicon dioxide, chromium oxide,aluminum oxide, titanium oxide, tantalum oxide, zirconium oxide, oryttrium oxide can be applied with use of a mask over the top of themetal layer to electrically isolate the desired spectral filter materialarea from other conductive portions. This electrical insulation materialis not applied to, or removed from, portions of the spectral filtermaterial or admission/conductivity promotion material where electricalconductivity is desired.

One method to reduce the size of, or to eliminate the need for, thebezel is to make an element with substantially no offset between theperipheral edges of the first and second substrates using anelectrically conductive material as a portion of the electrical bus. Inorder to use the preferred electrically conductive material, anisolation of a portion of the conductive materials on the second and/orthird surfaces needs to take place. The second and third surfaces wouldbe shorted together by the electrically conductive material if oneportion of each surface were not isolated in non-overlapping areas. Thethird surface may be electrically isolated on one side of the elementand the second surface would be electrically isolated on an opposite oradjacent side of the element. Preferably, a laser is employed to removeconductive material from the desired areas. The laser separation ispreferably located between the electrically conductive material and thevisibly active area of the element. More preferably the separation areais located such that an anode and cathode are not coexistent on the samesurface and in contact with the electro-optic medium. When an anode andcathode are located on the same surface with the addition of an anode ora cathode on the adjacent surface, a residual slow to erase color willbe present along the separation area. Additionally, with an anode on thesecond surface and the third surface between the seal and the separationarea, the color produced by the anode is visible between the primaryseal material and the separation area. Likewise, if a cathode is locatedon the third surface and the second surface between the primary sealmaterial and the separation area, the color produced by the cathode isvisible from the front between the separation area and the primary sealmaterial.

In mirror elements having a spectral filter material between the viewerand the primary seal material, a separation area may be incorporated.With the spectral filter material on the first surface, the mirrorelement is made much the same as described with regards to elements thatdo not include a spectral filter material. The separation areas are notvisible when looking at the first surface. When the spectral filtermaterial is proximate the second surface, the separation area is visiblewhen looking at the first surface.

A typical laser defined separation area is between 0.005-0.010 incheswide. By making the separation area 0.002-0.004 inches wide, it is muchless noticeable. Even more preferable would be an isolation line of lessthan 0.002 inches so as to be virtually unnoticeable from the driver'sperspective. Material can be removed to create an electrical isolationline using a variety of techniques including masking during coatingdeposition, media blasting, laser ablation, mechanical abrasion,chemical etching, or other methods known in the art. Photolithography incombination with chemical, reactive ion or other etching method couldproduce isolation lines below 1 um in width. It should also be notedthat shorter wavelength lasers can be focused to create a smaller spotsize. This provides for a more narrow and less visible electricalisolation line. As the isolation line becomes more narrow, it may becomeincreasingly difficult to achieve complete electrical isolation betweenthe first and second conductive portions. The resistance between the twoconductive portions can be easily measured using an ohmmeter. For atypical electro-optic mirror element, it is preferred that thisresistance is greater than 30 ohms. It is more preferred that thisresistance is greater than 100 ohms. Complete electrical isolation ismost preferred. The separation area is preferably located within theprimary seal material area and extends the length of the element toprovide a large electrical contact area. When the separation area islocated over the top of the primary seal material area, the color ortransparency of the seal can be adjusted to help hide the separationarea. This separation area may be incorporated into artwork or text onthe mirror element. A separation area may be incorporated into adisclaimer on the mirror element, a manufacturer's emblem, or othergraphic and/or text. It should be understood that the laser line may bepositioned along the inner edge of the spectral filter material. In thisconfiguration, the majority of the laser line is not visible because thelaser line coincides with the edge of the spectral filter material. Someresidual color is present after clearing the electro-optic media on thesame substrate; however, most of the colored area is hidden from viewbehind the spectral filter material. The only laser line portions thatare visible are short line segments made through the spectral filtermaterial near the edge in two places.

It is also generally desirable to position the electrode isolation line,such as a laser ablation line in an area of the mirror, outside of thespecified field of view of the mirror. There are legal guidelines in theUnited States, Europe and in other countries for the minimum area to theside and rear of a vehicle that must be visible in a mirror. This areacan be projected onto the surface of the mirror and objects that arewithin the boundaries of that projection must be visible to the driver.This projection generally takes the shape of a triangle and the size ofthe projection can be larger or smaller depending on whether the mirrorsurface is flat or bent. FIG. 3(A) details the shape (identified withdashed line 311 a) of a typical specified minimum field of viewprojection for a left hand outside electrochromic mirror with a bezel.Since the bezel area is not reflective it cannot be included in thefield of view of the mirror. However, the bezel area can be covered witha spectrally reflective coating such as a metallic ring on surface two.As long as this reflective ring has a high enough reflectance to meetthe minimum reflectance standards for the particular country, this areacould be considered field of view. As described previously, the mirrorcould then be made smaller by the bezel width while maintaining the samespecified field of view. Again, it would be preferable to locate anyvisible electrode isolation lines outside of the projection of thespecified field of view of the mirror.

Another way to isolate the electrically conductive material is to use anonconductive layer between the electrically conductive material and thesurface to be isolated, such as a vacuum deposited dielectric ink, or athinned layer of a nonconductive epoxy or other resin. It may bedesirable to employ a separation area proximate the third surfacebecause the separation area is not visible looking at the first surface.By using a nonconductive material on the second surface, there is noneed for a first separation area. This is particularly desirable whenthe second surface has a spectral filter material. By thinning anonconductive epoxy, a very thin layer can be obtained. This isimportant because enough area needs to be provided to apply theelectrically conductive material. Preferably, the nonconductive epoxy isonly flash cured. For example, place the material in an 85° C. oven forapproximately two minutes. If the nonconductive epoxy is fully cured andis partially covering an area that is in contact with the primaryassociated spacer beads, an undesirable, non-uniform cell spacing may becreated. By not curing the nonconductive material completely, the spacerbeads will more easily penetrate the layer during the final cure, andnot affect the cell spacing.

An external electrical connection may be made to the third surface of anelectro-optic mirror element having a second surface spectral filtermaterial by extending at least a portion of the third surface conductiveelectrode under the primary seal material area and over the perimeteredge of the second substrate. When coating (such as by vacuumsputtering) over the edge of a piece of glass, the conductivity of thecoating tends to decrease over a sharp edge or rough surface. Also, thecoating process does not typically provide a durable coating on the sideor edge of the glass. To do this without losing conductivity, a goodseam or polish on the substrate corner and/or edge is helpful to providea smooth transition from the third surface to the edge. A rough groundsurface without polishing has lower conductivity at a typical thirdsurface coating thickness. The smoother the surface and transition fromthe third surface to the edge, the better the conductivity. A sputtertarget mounted to coat the edge of the glass during the coating processis also helpful to provide a more uniform and durable coating.

It is conceivable that the coating could be extended over the edge ofthe glass and onto the back of the glass such that the electricalconnection to the third surface could be made on that back of the mirrorelement. A reflective third surface is typically more conductive than asecond surface conductive electrode; therefore, an electricallyconductive material may not be needed. Therefore, the primary sealmaterial may be dispensed up to the edge of the substrate. Having thethird surface material extending onto the edge may only be on one side.The opposite substrate may comprise a separation area and electricallyconductive material to the third surface since it is not visible.

With the third surface material extended onto the edge of the substrate,an L clip in lieu of a J clip can be used since there is no need to havea clip portion inserted between the second and third surfaces. The Lclip only needs to be long enough to contact the conductive portion onthe edge. A conductive epoxy could be used to bond to the third surfacematerial on the edge to the L clip. A pressure sensitive adhesive couldbe used on the back of the L clip to secure it to the fourth surface.Alternatively, solder could be applied directly to the coating on theedge or back of the mirror. In one embodiment, the solder could be usedas both the contact and as a conductive bus system.

One advantage of making external electrical contact to the third surfacematerial extended onto the edge of the substrate is that a conductivematerial is no longer required adjacent to the primary seal for filtermaterial on the first or second surface may be narrower while stillcovering the primary. Although a typical spectral filter material mayvary from 4 to 8 mm in width, it may be aesthetically pleasing to reducethis width below 4 mm. As the width of the primary seal is reduced, thewidth of the spectral filter material may also be reduced. Usingassembly and sealing techniques previously disclosed, it is possible toreduce the primary seal with to less than 1 mm which allows for aspectral filter width of less than 1 mm.

Another way to make electrical connection to the third surface isolatedfrom the second surface is to use a conductive ink or epoxy to connectthe third surface to the edge. Thinning the conductive ink or epoxy andapplying it to the edge of the substrate contacts the third surface₇without contacting the second surface. With this thinned conductiveepoxy, a conductive path can be applied such that contact is made on theedge or the back of the mirror element. An L clip may be applied contactand cured in place. A pressure sensitive adhesive may be used to securethe L clip in place during the curing process and to provide strainrelief with connecting wires.

If the corrosive effects of the environment on the metal can beminimized, very thin metal films or foils can be used to establish astable interconnect to the conductive adhesive or bus. This metal foilor metal film on a plastic foil could be conformed to the shape of the Jclip or other desired shape (without the need of expensive forming dies)and adhered to the substrate with an adhesive such as a pressuresensitive. This metal foil or metal film on plastic foil may be in theform of a roll of adhesive tape that is cut to size and applied to theEC element substrate such that one end comes in contact with theconductive bus that is in contact with the front and/or backelectrode(s). A spade connect or wire may be attached to the other endof the metal foil or film by traditional methods such as soldering orconductive adhesive, or the end of the metal foil or tape may connectdirectly to the voltage source for the EC element such as a printedcircuit board.

At least one embodiment of a formable contact comprises 0.001″ palladiumfoil (Aldrich chemical Milwaukee, Wis.) laminated to 0.002″ acrylicdouble-sided adhesive tape with a release liner (product 9495 200 MPseries adhesive 3M Corporation, Minneapolis, Minn.). The metal foil tapemay be cut to an acceptable size for application on an electrochromicdevice. The metal foil or metal film on plastic foil tape may also beprecut to a form or shape if desired.

At least one embodiment of a formable contact may be made from a plasticfilm and metallized with a metal such as gold, silver, titanium, nickel,stainless steel, tantalum, tungsten, molybdenum, zirconium, alloys ofthe above, or other metals or metal alloys that resist salt spraycorrosion. Also, palladium or other platinum group metals such asrhodium, iridium, ruthenium, or osmium may be used.

At least one embodiment of a formable contact uses a polymer carriercomprising 0.002″ polyimide tape (#7648A42 McMasterCarr, Chicago, Ill.)coated with chrome and with any platinum group metal such as rhodium,indium, ruthenium, or osmium as the base, and then coated with a layerof silver, gold or alloys thereof. This system is solderable and hassufficient flexibility to wrap around the glass edge from one substratesurface to another surface.

At least one embodiment comprises a conductive coated polymerfilm-produced for the flexible circuit industry. In at least oneembodiment, Sheldahl (Northfield, Minn.) produces combinations ofpolyimide (Kapton) and polyester films coated with ITO, aluminum,copper, and gold. Polyimide tapes coated with a base metal may be platedor coated with different metals or alloys to improve durability and/orsolderability. These films can be coated with an adhesive or laminatedto double-sided tape as described above. This metallized foil can bebent around a glass edge and maintain good conductivity.

At least one embodiment using a fibrous substrate is comprised of asolvent-based ink placed onto a fiber backing. The conductive ink iscomprised of 10 parts methyl carbitol (Aldrich Milwaukee, Wis.), 2 partsBis A-epichlorhydrin copolymer (Aldrich Milwaukee, Wis.), and 88 partsof LCP1-19VS silver epoxy flake. The conductive ink may be applied tofibrous material such as those comprising glass, metal, or cellulose.The system is heated sufficiently to evaporate the solvent. Theconductive and flexible formable contact is then applied to one surface,wrapping around to another surface.

At least one embodiment of a polymeric formable contact incorporates aconstruction mechanism to either protect the metal, hide the metalcolor, or offer another color more appealing to the outside appearanceof the glass edge. This construction would incorporate a polymeric filmon the outside, followed inwardly by the metal coating, and followedinwardly by an adhesive. The metal coating within the system would needto have an exposed edge for making contact to one of the glass insideconductive surfaces. Contact to this end could be made with an appliedconductive adhesive, solder, or other method to make a stable electricalcontact. The opposite end could have contact made with conductiveadhesive, solder, or other mechanical means.

In relation to the conductivity of a conductive polymer or composite,there are methods to describe the conductive polymer or composite'sconductivity. Those skilled in the art of Isotropic and anisotropicconductive adhesives commonly use a 4-pin probe for the resistancemeasurement. A common unit of measurement in the field of conductiveadhesives is ohms/square/mil. This measurement is expressed as not onlya factor of width, but also of thickness. This measurement, whenperformed on a nonconductive substrate, expresses the linearconductivity of a conductive polymer or composite such as a metal orcarbon or metal oxide conductive particle-filled epoxy.

Another method by which to determine conductive polymer effectivenessfor use as a bus is to utilize isolated conductive pads and bridge theseisolated pads using the conductive polymer. A particular way to performthis test is to isolate conductive coatings on glass with laserablating, physical scoring, or chemical removal. The uncured conductivepolymer is applied to bridge the conductive pads so that the currentpath must pass through multiple contact interfaces, but is stillisolated from itself so as to not short the bridges together. Aresistance reading is taken at the ends across the test piece.

Not all conductive polymers with high conductivity measured by theohm/sq/mil method have adequate interfacial electric contact to theelectrode surfaces used in an electrochromic device. Based on the abovecoupon using an ITO electrode as the isolated conductive pad, anacceptable resistance would be less than 1000 ohms. A more preferredresistance is less than 500 ohms, and an even more preferred resistanceis less than 200 ohms.

There are methods to affect this interfacial conductivity through theselection of conductive polymer components. The shape of the metalpowder or flake can affect the interfacial contact. Additives can alsoaffect the interfacial contact. Coupling agents, curing catalysts orcross linkers, epoxy resin systems, and methods by which to process thesilver epoxy can have an affect on the conductive polymer's ability tomake electrical contact to an adjacent conductive surface.

In at least one embodiment, a silver epoxy comprises 3 partsHexahydrophthalic anhydride (Aldrich, Milwaukee, Wis.), 2.14 partsAniline glycidyl ether (Pacific Epoxy Polymers), 0.1 parts Benzyldimethyl amine (Aldrich chemical, Milwaukee, Wis.), and 23.9 partssilver flake LCP1-19VS (Ames Goldsmith, Glens Falls, N.Y.). When testedusing an ohm/square/mil conductivity measurement, results are acceptable(approximately 0.020 ohm/sq/mil).

In another embodiment, U.S. Pat. Nos. 6,344,157 and 6,583,201 disclosethe use of corrosion inhibitors, oxygen scavengers or metal chelatingagents for use in conductive adhesives.

In some cases, additives can be added to silver epoxies to stabilize orimprove conductivity. In at least one embodiment, a silver epoxycomprising 3.4 parts Bis F epoxy resin (Dow Corporation, Midland,Mich.), 1.1 parts (Air Products and Chemicals, Allentown, Pa.), 20.5parts silver flake (Ames Goldsmith, Glens Falls, N.Y.), and 0.03 partsDiethanolamine (Aldrich, Milwaukee, Wis.). Results are acceptable forboth conductivity (approximately 0.020 ohms/square/mil) and interfacialcontact (approximately 190 ohms).

As mentioned elsewhere in this patent, a sputtered or vacuum-appliedmetal coating can be extended beyond the seal and over the edge of theglass to be used as an electrical connection. The metal coating shouldmeet the criteria of corrosion-resistant metals listed above. Theelectrical connection to this coating could be made with a spring clip,or solder could be applied directly to the metal coating.

At least one embodiment of a solderable metal coating on glass, chromeis coated as the base layer then coated with any platinum group metalsuch as rhodium, irridium, palladium, ruthenium, or osmium, or copper,silver or gold, or alloys of the above are solderable using tin/leadsolders.

In another embodiment, chrome is coated as the base layer, then coatedwith any platinum group metal such as rhodium, irridium, palladium,ruthenium, or osmium, then coated with copper, silver or gold or alloysof the above are solderable using tin/lead solders.

In current automotive construction, restrictions exist using lead-basedcomponents such as solders. Other solders such as tin/zinc tin/silver,indium-based solders containing silver, bismuth, tin, zinc, copper, andor antimony; silver solders or other non-lead containing alloys may beused as a solder material. Soldering systems that may be employed areinductive heat, IR heat, ultrasonic, wave soldering or a soldering iron.

Another advantage to having a thinner conformable conductive bus clipmaterial as an electrical interconnect to the conductive epoxy is toreduce distortion in the reflection of the first substrate particularlywhen the first element is larger than the second element. Distortion canbe generated as a result of high temperature seal curing and differencesin the coefficients of thermal expansion between the seal and theconductive clips. The thicker the clip material, the more distortion isseen, particularly when using more flexible substrates. A thinner clipmaterial also has the advantage of being less noticeable if it is usedto wrap around the 3^(rd) surface to the back of the mirror. This isparticularly relevant if the first and second elements are aligned atthe point the clip wraps around. When the first element extends past thesecond element, the clip can be hidden entirely from view.

Example: An electrochromic mirror was made with flat 1.6 mm thick glassfor both front and rear elements. The front element was cut 0.040″larger (offset) on three sides. The inboard side (the side closest tothe driver) had no offset to facilitate easier filling and plugging ofthe part. A 0.001″×0.5″×0.75″ silver foil with 0.002″ thick pressuresensitive adhesive was applied on the top and bottom of the secondelement. The conformable conductor contacted 0.010″-0.030″ of surfacethree then wrapped around to the fourth surface. A primary seal materialwas then dispensed around the perimeter of the first element leavingapproximately 0.040″ for an offset on three sides and an additional0.040″ between the seal material and the edge of the glass element onboth the top and bottom edge of the second surface of the first element.The second element was then attached to the first element leaving a0.006″ space between the elements. The seal material was cured to fixthe elements in this spaced-apart relationship. After cure of theprimary seal, a conductive epoxy was then injected into the part fromthe edge on the top and bottom of the part, thereby encapsulating andmaking electrical contact with the third surface portion of theconformable conductor. It should be noted that this process ofdispensing a primary seal and a conductive seal could be accomplishedmore readily and easily on a dual dispense system, dispensing bothepoxies at the same time. The conductive epoxy was then cured. Themirror was inspected for distortion of the first surface reflection overthe conformable conductor, and no distortion was found. When similarmirrors were constructed using either nickel, stainless steel or copperclips with a 0.003″ thickness, visual distortion can be seen near theperimeter of the first surface in the area directly above the clip.

As mentioned elsewhere herein, establishing electrical contact to thesecond and third surface conductive electrodes typically involvescoordination of a number of individually designed components. Turning toFIGS. 36(A-I), various options for electrical clips are depicted. Theplacement of the electrical clips is discussed throughout thisdisclosure in concert with the electrically conductive material.

A preferred electrically conductive material comprises 27.0 g Dow 354resin—a bis phenol F epoxy functional resin. Viscosity is preferably˜4000 cP 9.03 g Air Products Ancamine 2049—a cycloaliphatic amine cureagent. Viscosity preferably is ˜60 cP, 164 g Ames Goldsmith LCP 1-19VSsilver—a silver flake with tap density ˜3 g/cc and average particle size˜6 microns.

As described herein, at least one embodiment comprises a perimetermaterial surrounding the periphery of the element. A preferred perimetermaterial comprises 120 g Dymax 429 with some fillers added (i.e., 0.40 g6-24 silver flake available from Ames Goldsmith, 1.00 g silver-coatedglass flake (i.e., Conduct-o-fil available from Potters Industries),12.0 g crushed SK-5 glass filler available from Schott Glass or acombination thereof crushed into a powder and sieved with a 325 mesh).This material can be applied to the mirror edge using a number oftechniques. One technique is to load the material into a 30 cc syringewith a needle (˜18 gage). The needle can be oriented in a verticalposition such that the perimeter material is dispensed with air pressure(<50 psi) onto the edge of the element while the element is beingmechanically rotated on a robot arm or other mechanical device. Theapplied edge material can then be cured with UV light. Complete cure canbe accomplished in 20 seconds or less. A robot may also be employed torotate the part as it is being cured to prevent sagging.

The intent of the perimeter material is to protect the bus components;hide visible components like electrically conductive materials, clips,seals, glass edges; to protect the cut edge of glass and offer anappealing visual appearance of the mirror element. This may also beachieved with use of conventional plastic bezels, grommets, elastomericbezels and the like.

Many different materials (such as epoxy, silicone, urethane, acrylate,rubber, hotmelt) and cure mechanisms can be used for this edgetreatment. The preferred cure method is by UV radiation. If fillers,dyes, or pigments that are partially opaque to UV radiation are used, acombination UV thermal cure can be used. Fillers such as glass orreflective silver aid the penetration of UV light by transmission,scattering or internal reflection, and are preferred for good depth ofcure. Preferably the perimeter material has a gray color or appearancesimilar to that of a ground glass edge or is dark or black in color.Colors may be varied by use of organic dyes, micas, impregnated micas,pigments, and other fillers. A darker, more charcoal appearance may beachieved by selecting different fillers and different amounts of filler.Less crushed glass will darken and flatten the color of the aboveformulation. Use of only crushed glass (or flakes or other glassparticle) with a different refractive index than the edge material resinbinder will give the appearance of a ground glass edge, or rough penciledge. Some additives are denser than the media they are contained in.Fumed silicas can be added to help prevent settling of the heaviercomponents (metal and glass particles); 2 percent by weight of fumedsilica was found to be sufficient in the preferred method.

Other ways to apply the perimeter material to the element edge includeapplying the material with a roll, wheel, brush, doctor bar or shapedtrowel, spraying or printing.

The perimeter edge materials chosen for a vehicular exterior applicationpreferably meet the following test criteria. These criteria simulate theexterior environment associated with a typical motor vehicle: UVstability (2500 kJ in UV weatherometer)—no yellowing or cracking orcrazing of material when exposed to direct UV; heat resistance—little orno color change, no loss of adhesion; humidity resistance—little or nocolor change, no loss of adhesion; thermal-cycling—no loss of adhesion,no cracking; CASS or salt spray—protection of the underlying metalcoatings and conductive epoxy systems, no loss of adhesion and novisible sign of underlying corrosion; and high pressure water test(Steam Autoclave Test, at least 200 F/10 psi—described in more detailelsewhere in this document)—no loss of adhesion after parts have beentested in previous stated testing.

With further reference to FIGS. 35(A-N), various embodiments forconfiguration of second and third surface electrode contacts are shown.FIGS. 35(A-N) depict configurations similar to that discussed elsewhereherein having a first surface stack of materials, a second surface stackof materials, a third surface stack of materials and/or a fourth surfacestack of materials. The word “stack” is used herein to refer tomaterials placed proximate a given surface of a substrate. It should beunderstood that any of the materials as disclosed in commonly assignedU.S. Pat. Nos. 6,111,684, 6,166,848, 6,356,376, 6,441,943, 6,700,692,5,825,527, 6,111,683, 6,193,378, 6,816,297, 7,064,882 and 7,324,261, thedisclosures of which are incorporated herein by reference, may beemployed to define a unitary surface coating, such as a hydrophiliccoating. Preferably, second, third and fourth surface stacks are asdisclosed herein or in commonly assigned U.S. Pat. Nos. 5,818,625,6,111,684, 6,166,848, 6,356,376, 6,441,943 and 6,700,692, the disclosureof each is incorporated in its entirety herein by reference.

FIGS. 36(D-I) depict various embodiments for configuration of the anodeand cathode connections to the second and third surface conductiveelectrodes, respectively. Preferably, the sheet resistance of the thirdsurface conductive electrode is less than that of the second surfaceconductive electrode. Therefore, the cathode contact area may besubstantially less than the anode contact area. It should be understoodthat in certain embodiments, the anode and cathode connections may bereversed.

The configuration of FIG. 35(J) may be used to construct a no-bezel ornarrow-bezel rearview mirror assembly that does not incorporate aspectral filter. If the perimeter seal and electrode contact means 3548j 1, 3548 j 2 were both substantially moved to the mirror edge, there isnot a requirement for a spectral filter material to cover theseal/contact area. When this approach to mirror element construction isused, the mirror element darkens substantially completely to theperimeter edge during glare conditions. In this approach most or all ofthe seal and contact area can be substantially moved from the perimeterof mirror substrate one, surface two and substrate two, surface three,to the edges of substrate one and substrate two.

In at least one embodiment, the top edge of the first substrate and thebottom edge of the second substrate were coated with a conductive epoxyto transfer electrically conductivity from the conductive electrode oneach substrate to the substrate edge. The conductive epoxy is preferablyformulated using: 3.36 g D.E.R. 354 epoxy resin (Dow Chemical, Midland,Mich.), 1.12 g Ancamine 2049 (Air Products and Chemicals, Reading, Pa.)and 20.5 g of silver flake with an average particle size of 7 micronstap density of 3.0-4.0 g/cc was thoroughly mixed into a uniform paste.This conductive epoxy mixture was thinned with enough toluene to producea low viscosity conductive paint that could easily be applied to thesubstrate edge. The coated substrates were put in a 60° C. oven for 15to 20 minutes to evaporate the toluene.

A uniform layer of an epoxy that was sparsely filled with conductiveparticles (Z-axis conductor) was applied to 0.001″ thick copper foil.The Z axis epoxy (5JS69E) was formulated as follows: 18 g of D.E.N. 438,2 g D.E.N. 431 (Dow Chemical, Midland, Mich.), 1.6 g of US-206 fumedsilica (Degussa Corporation, Dublin, Ohio), 6.86 g Ancamine 2049 and10.0 g silver flake FS 28 (Johnson Matthey, Royston, Hertfordshire, UK)was blended into a uniform paste. The silver flake filler had a tapdensity of 2.3 g/cc and an average particle size of 23 microns. A curedthin film of this epoxy formulation becomes conductive in the z-axis andnot in the x or y axis. This z-axis conductive epoxy was thinned withenough toluene or THF solvent to produce a viscosity suitable to spreadinto a thin uniform thickness onto the copper foil. The solvent was thenevaporated off in a 60° C. oven for approximately 5 minutes. The epoxyremained slightly tacky after solvent evaporation. The edges of the twosubstrates were aligned with virtually no offset. The gap between thesubstrates was accurately maintained by using precision sized PMMA beadsas spacers. A small piece of Kapton tape approximately 2 mm wide wasused on one end extending across the edges of both substrates and thecell spacing. The Kapton tape would eventually be removed from the cellafter assembly and the Kapton tape area, which was not wetted withepoxy, would be used as a fill port. The copper foil with the z-axisconductive epoxy was then applied to the peripheral edge of the partsuch that the epoxy wetted both substrate edges completely. The elementwas then cured in an oven at 200° C. for 15 minutes. After the cure, asmall separation was made in the copper foil on each side toelectrically isolate the copper foil on the top from the copper foil onthe bottom of the part. The copper foil covering the Kapton tape and theKapton tape were removed. The opening created by the removed Kapton tapewas used to fill the part. The opening was then plugged with an UVcurable adhesive. The opening on the opposite side was also plugged withan UV curable adhesive but before filling.

FIGS. 36(A-N) depict various embodiments for configuration of anelectrical clip. Generally, the individual clips are depicted to definesubstantially a “J” shaped cross section.

The embodiment of FIG. 36(A) depicts a J-clip 3684 a configured toaccommodate an electrical connection post (not shown) fixed thereto. Inat least one embodiment, the first and second electrical clips areconfigured in combination with a carrier plate (as described in detailherein with respect to FIGS. 38(A)-38(C)) to form a “plug” typeelectrical connector. The J-clip comprises an edge portion 3683 a and aninner element portion 3682 a. The inner element portion is configured tobe positioned between a first and second substrate and to be inelectrical contact with an electrically conductive epoxy, solder orconductive adhesive to make electrical contact with either a second orthird surface stack of materials.

FIG. 36(B) depicts a series of apertures 3685 b extending through aninner element portion 3682 b in order to facilitate, at least in part, amechanical and/or electrical contact with an electrically conductivematerial. The J-clip 3684 b comprises a wire connection feature 3686 band an edge portion 3683 b. The wire connection feature may beconfigured to either accommodate a solder or a crimp-type wireconnection.

FIGS. 36(C-E) depict various J-clip configurations 3684 c, 3684 d, 3684e comprising an electrical connection stab 3686 c, 3686 d, 3686 e havinga friction fit hole 3687 c, 3687 d, 3687 e. Each J-clip has an edgeportion 3683 c, 3683 d, 3683 e and an inner element portion 3682 c, 3682d, 3682 e. FIG. 36(C) depicts having a portion 3685 c of the J-clipfolded such that the J-clip is not as long and is taller than the J-clipof FIG. 36(D). FIG. 36(E) depicts a series of apertures 3681 e extendingthrough a third portion of the clip to provide a stress relief area toaccommodate variations in material coefficients of expansion.

FIG. 36(F) depicts a raised portion 3685 f on a J-clip 3684 f along witha wire crimp 886 f configured to spatially separate the wire contactarea from the element. This J-clip comprises an edge portion 3683 f andan inner element portion 3682 f.

FIG. 36(G) depicts a J-clip 3684 g comprising a wire crimp 3686 g, anedge portion 3683 g and an inner element portion 3682 g. FIG. 36(H)depicts a J-clip 3684 h comprising a wire crimp 3686 h, an edge portion3683 h and an inner element portion 3682 h. The inner element portioncomprises a series of apertures 3681 h to facilitate enhanced mechanicaland/or electrical contact. FIG. 36(I) depicts a J-clip 3684 i comprisinga wire crimp 3686 i, an edge portion 3683 i and an inner element portion3682 i. FIG. 36(J) depicts a J-clip 3684 j comprising a wire crimp 3686j, an edge portion 3683 j and an inner element portion 3682 j.

FIG. 36(K) depicts a J-clip 3684 k similar to that of FIG. 36(A) excepthaving a longer portion for adhering to a substrate. This J-clipcomprises an edge portion 3683 k and an inner element portion 3682 k.

FIG. 36(L) depicts a J-clip 36841 having two large apertures 36861 forstress relief along with four bumps 36871 for enhancing electricalconnection placement. This J-clip comprises an edge portion 36831 and aninner element portion 36821.

FIG. 36(M) depicts a J-clip 3684 m comprising a wire crimp 3686 m, anedge portion 3683 m and an inner element portion 3682 m. FIG. 36(N)depicts a J-clip 3684 n comprising a wire crimp 3686 n, an edge portion3683 n and an inner element portion 3682 n.

Electro-optic mirrors often incorporate a bezel that covers the edge ofthe mirror element and the electrical bus connections. In addition, themirror edge and bus connection are often encapsulated in a pottingmaterial or sealant. As long as the mirror remains functional, theaesthetics of the mirror edge and bus connection are not a concern. Incontrast, Electro-optic mirrors without a bezel typically have both themirror element edge and the associated electrical bus connectionsexposed to the environment. The bus connection typically utilizes ametal member (the term “metal” throughout this discussion on corrosioncan represent a pure metal or a metal alloy) such as a formed clip orstrip. Electro-optic mirrors with bezels often have formed metallicclips or strips made of copper or copper alloy. The appearance andcorrosion resistance of these formed clips or strips becomes importantif good aesthetics are to be maintained over the life of the vehicle.Copper and copper alloys tend to corrode and turn green in the salty wetenvironments to which an EC outside mirror is exposed. This is notaesthetically acceptable. Even if the metal bus cannot be vieweddirectly, the formed metal clips or strips are typically made of thinmaterial, usually less than 0.010″ thick and more typically 0.005″ orless in thickness. These thin metal pieces can corrode quickly resultingin structural failure, loss of spring electrical contact force or lossof electrical continuity. This issue can be minimized if the edge of themirror and/or back of the mirror is covered with a paint or coating. Themetal clip could also be protected from the environment with a coatingsuch as a conformal coating, paint or varnish or metal plating orcladding. Examples of suitable conformal coatings are:

-   -   1. UV curing epoxy system comprising of 354 bis F resin (Dow        Chemical) with percent (by weight) of US-206 (Degussa) and 3        percent (by weight) of UVI-6992 (Union Carbide        Corporation—subsidiary of Dow Chemical). 0 . . . 3 percent (by        weight) of US-206 and 2 to 5 percent (by weight) of UVI-6992.    -   2. Solvated urethane conformal coating like Humiseal 1A33 (Chase        Corporation, Woodside N.Y.).    -   3. Solvated polyisobutylene comprising of 3 parts (by weight)        pentane and 1 part (by weight) Vistanex LM-MS-LC (Exxon        Chemical).

Examples of protective metal platings include gold, palladium, rhodium,ruthenium, nickel and silver. In general these coatings or surfaceplatings retard the corrosion and extend the useful life of theelectrical bus; however, corrosion often eventually occurs. Anotherapproach to extending useful bus life is to make the bus clip or stripout of a metal or metal alloy that has good corrosion resistance insalty environments. Suitable metals include the noble metals and noblemetals alloys comprising gold, platinum, iridium, rhodium, ruthenium,palladium and silver as well as metals and metal alloys of titanium,nickel, chromium, molybdenum, tungsten and tantalum including stainlesssteel, Hastalloy C, titanium/aluminum alloys, titanium palladium alloys,titanium ruthenium alloys. Zirconium and its alloys also perform wellunder certain circumstances. A table ranking a number of these metalsand metal alloys after the copper accelerated salt spray (CASS) testingis included herein. The rankings have the following meanings:4—unacceptable corrosion, 3—corrosion evident but acceptable, 2—lightcorrosion evident, and 1—very light/no corrosion.

Corrosion Ranking Table Material Plating Ranking Olin 725 (Cu—Ni—Sn)None 4 Olin 638 (Cu—Al—Si—Co) None 4 Olin 194 (Cu—Fe—P—Zn) None 4 Olin510 Phos. Bronze (Cu—Sn—P) None 4 Olin 713 None 4 Phos. Bronze Tin 4Olin 770 German Silver (Cu—Zn—Ni) None 3 Olin 752 (Cu—Zn—Ni) None 3Monel (Ni—Cu) None 3 Brush Wellman (Cu—Be) None 4 174-10 Palladium 3174-10 Silver 3 174-10 Tin 4 302 Stainless Steel None 2 302 StainlessSteel Tin 3 302 Stainless Steel Silver 3 302 Stainless Steel Rhodium 2302 Stainless Steel Nickel Strike 1 302 Stainless Steel Passivated 2Surface by JS 316 Stainless Steel None 2 Tin Foil None 3 Silver FoilNone 1 Nickel None 1 Titanium Unalloyed (grade 1) None 1 TitaniumUnalloyed (grade 2) None 1 Titanium Unalloyed (grade 4) None 1 Ti—6AI—4V(grade 5) None 1 Ti—3AI—2.5V (grade 9) None 1 Ti—0.15—Pd (grade 11) None1 Ti—0.15Pd (grade 16) None 1 Ti—0.1Ru (grade 26) None 1Ti—3AI—2.5V—0.1Ru (grade 28) None 1 Ti—6Ai—4V—0.1Ru (grade 29) None 1Molybdenum Foil None 2 Gold Foil None 1 Rhodium Foil None 1 Lead FoilNone 3 Tungsten Foil None 1 Palladium Foil None 1 Cobalt Foil None 4Tantalum Foil None 1 Nickel Foil None 1 Nickel Foil Silver 1 316Stainless Steel Tin 3

When the bus interconnection technique incorporates the use of two ormore different metals in close contact with one another, the effects ofgalvanic corrosion are preferably considered. Many interconnectiontechniques utilize conductive adhesives. These adhesives generally areorganic resins such as epoxy, urethane, phenolic, acrylic, silicone orthe like that are embedded with conductive particles such as gold,palladium, nickel, silver, copper, graphite or the like. Unlike a metalsolder joint, organic resins breathe. Moisture, oxygen and other gassescan diffuse through organic resins and cause corrosion. When dissimilarmetals are in contact with one another, this corrosion may beaccelerated by the difference in the electrochemical potential of themetals. Generally, the greater the difference in electrochemicalpotential between the metal, the greater the probability of galvaniccorrosion. It is therefore desirable to minimize the difference inelectrochemical potential between metals selected for use in a bussystem, especially when a naturally non-hermetic electrically conductiveadhesive is used. When one or both of the metals are plated, it ispreferred that a plating material is selected that has anelectrochemical potential in between the electrochemical potentials ofthe two metals. For office environments that are humidity andtemperature controlled, the electrochemical potentials differencesbetween the metals are preferably no more than 0.5 V. For normalenvironments, the potential difference is preferably no more than 0.25V. For harsh environments, the potential difference is preferably nomore than 0.15 V. Many conductive adhesives use silver particulate orflake as the conductive filler. Silver represents a good compromisebetween cost and nobility. Silver also has excellent conductivity. Asdescribed in metals galvanic compatibility charts such as those suppliedby Engineers Edge (www.engineersedge.com) and Laird Technologies(www.lairdtech.com), silver has an anodic index of 0.15 V. Tin-platedcopper or copper alloy that is typically used for bus connections inbezeled mirrors has an anodic index of 0.65 V. When tin plated copper isused in contact with silver, the large 0.5 V anodic potential differenceis acceptable for use in controlled office-like environments. Theenvironment associated with outside vehicular mirrors is by no means acontrolled environment. A potential difference of less than 0.45 V isdesirable, a difference of less than 0.25 V is preferred and adifference of less than 0.15 V is most preferred.

Metals Galvanic Compatibility Chart Anodic Metal Surface Index Gold,solid and plated, gold-platinum alloy, graphite carbon 0.00 Rhodiumplated on silver 0.05 Rhodium plating 0.10 Silver, solid or plated; highsilver alloys, monel, high nickel-copper alloys 0.15 Nickel, solid orplated, titanium and s alloys, monel, nickel-copper alloys, titaniumalloys 0.30 Copper, beryllium copper, cooper; Ni—Cr alloys; austeniticcorrosion-resistant steels; most 0.35 chrome-poly steels; specialtyhigh-temp stainless steels, solid or plated; low brasses or bronzes;silver solder; German silvery high copper-nickel alloys Commercialyellow brass and bronzes 0.40 High brasses and bronzes, naval brass,Muntz metal 0.45 18 percent chromium type corrosion-resistant steels,common 300 series stainless steels 0.50 Chromium plated; tin plated; 12percent chromium type corrosion-resistant steels; 0.60 Most 400 seriesstainless steels Tin-plate; tin-lead solder 0.65 Lead, solid or plated,high lead alloys 0.70 Aluminum, wrought alloys of the 2000 Series 0.75Iron, wrought gray or malleable, plain carbon and low alloy steels;armco iron; cold-rolled 0.85 steel Aluminum, wrought alloys other thanthe 2000 Series aluminum, cast alloys of the silicon 0.90 type; 6000Series aluminum Aluminum, cast alloys other than silicon type, cadmium,plated and chromate 0.95 Hot-dip zinc plate; galvanized steel or electrogalvanized steel 1.20 Zinc, wrought; zinc-base die-casting alloys; zincplated 1.25 Magnesium & magnesium-base alloys, cast or wrought 1.75Beryllium 1.85 High brasses and bronzes, naval brass, Muntz metal 0.4518 percent chromium type corrosion-resistant steels, common 300 seriesstainless steels 0.50It should be noted that the potential differences between metalsdepends, at least in part, on the nature of the corrosive environmentthey are measured in. Results measured in, for example, seawater may beslightly different than for fresh water. It should also be noted thatthere can be large differences between passive and active surfaces ofthe same material. The anodic potential of a stainless steel surface maybe substantially reduced by a passivation treatment using nitric acidand/or solutions of oxidizing salts. The anodic potential difference maybe kept within the most preferred 0.15 V if silver is used incombination with, for example, gold, gold/platinum alloys, platinum,zirconium, carbon graphite, rhodium, nickel, nickel-copper alloys,titanium and monel. The potential difference may be kept within thepreferred 0.25 V with, for example, beryllium copper, brass, bronze,silver solder, copper, copper-nickel alloys, nickel-chrome alloys,austenitic corrosion resistant steels, and most chrome-moly steel. Thepotential difference may be kept within the desired 0.40V by using, forexample, 18-8 stainless steel or 300 series stainless steel, highbrasses and bronzes, naval brass and Muntz metal. When a plating isused, it is desirable to have the plating material within these anodicpotential ranges and most preferably have a potential between the twobase materials in close contact with each other. For example, gold,palladium, rhodium, ruthenium, nickel or silver plating generally meetsthese requirements. The electrical bus is generally connected to the ECmirror drive voltage source by use of a spade connector or solderedjoint. When a soldered joint, or connection, is used, the bus metal ispreferably solderable. Platings such as gold, palladium, rhodium,ruthenium, nickel, silver and tin can enhance the solderability of thebus clip. For instance, even though tin is not a preferred plating, atin-plated stainless steel bus clip solders easily when compared to aplain stainless steel clip. A solder-friendly, more preferredsubstrate/plating combination is stainless steel with palladium, silver,nickel or rhodium plating. Stainless steel with a nickel platingfollowed by a silver, palladium, gold, rhodium or ruthenium plating is apreferred material. Other preferred materials include metals or metalalloys comprising tantalum, zirconium, tungsten, and molybdenum with anickel, silver, gold, palladium, rhodium and ruthenium plating. Otherpreferred materials are metals, or metal alloys, comprising titanium ornickel with a nickel and/or silver plating. For enhanced stability, itis desirable to passivate the surface of the base metal.

Embodiments of Mounting Elements Including Bezel and Carrier.

Turning now to FIGS. 37(A, B), a mirror element comprising a firstsubstrate 3712 b and a second substrate 3702 b is depicted subsequent tobeing received by a carrier assembly. The carrier assembly comprises asubstantially rigid portion 3701 a, 3701 b integrated with a pliableperipheral gripping portion 3703 a, 3703 b. The substantially rigidportion and the pliable peripheral gripping portion may be co-molded,individually molded and adhered to one another, designed to friction fittogether, designed to interference fit together, individually molded andmelted together, or a combination thereof. In any event, the pliableperipheral gripping portion 3703 a, 3703 b is preferably designed toresult in an interface 3709 between the pliable peripheral grippingportion and the perimeter material beyond the crown 3713 such that fromnear the crown to near the tip 3707 there is a restraining forcegenerated that, at least in part, retains the element proximate thecarrier assembly as desired. An additional adhesion material 3705 a,3705 b may be utilized to further retain the element proximate thecarrier assembly. It should be understood that the perimeter portion3703 a, 3703 b may be constructed, at least in part, from a materialthat adheres to the perimeter material 3760 such that the retentiveforce is also generated along the interface 3711 on the rigid portion3701 a, 3701 b side of the crown 3703 a, 3703 b; in such a case, theperimeter portion 3703 a, 3703 b may extend short of the crown or justbeyond the crown as depicted in FIG. 37(B). Preferably, the perimeterportion tip 907 is tapered slightly to provide a visually appealingtransition to the element irrespective of whether the perimeter portionextends beyond the crown. It should be understood that the shape of theperimeter material may be altered to provide at least one edgesubstantially parallel to surface 3715 and the perimeter portion may bedesigned to impart a more pronounced transition between the crown andthe interface 3709.

FIG. 37(C) depicts an element comprising a first substrate 3712 c and asecond substrate 3702 c positioned within a carrier 3701 c and perimeterportion 3703 c. This configuration typically represents the as-moldedcondition of the pliable peripheral gripping portion. FIG. 37(B) wouldtypically represent the installed position of the pliable peripheralgripping portion. The installed position allows the pliable peripheralgripping portion to conform to the potential irregularities of the glassprofile. FIG. 37(B) is depicting a mechanical interlock between therigid portion of the carrier and the pliable peripheral grippingportion. This is useful for materials that are not intended to be bondedtogether whether adhered or bonded through a molding process. Themechanical interlocks can be spaced around the perimeter of the assemblyas needed. FIG. 37(C) is depicting a cross-section without a mechanicalinterlock. Both sections can be used as needed. Another differencebetween FIGS. 37(B, C) is the height of the pliable peripheral grippingportion off of the back side of the carrier. FIG. 37(B) limits theheight off of the back of the carrier of the pliable peripheral grippingportion by placing some of the pliable peripheral gripping portionbetween the glass and carrier in place of the heater/foam assembly. Thispotentially eliminates clash conditions inside the housing. FIG. 37(C)can be used to allow the heater/foam assembly to be placed to the edgeof the glass perimeter. This allows heating of the glass assembly allthe way out to the edge. However, it could potentially create clashconditions of the mirror assembly in the mirror housing.

Turning now to FIGS. 37(D-M), various carrier plates are depicted withperimeter gripping portions. FIGS. 37(D-G) depict a carrier plate 3701d, 3701 e, 3701 f, 3701 g having an integral perimeter gripping portion3703 d, 3703 e, 3703 f, 3703 g. In at least one embodiment, theperimeter gripping portion comprises a “goose neck” cross-section shapeand comprises a series of alternating lands 3703 d 1, 3703 e 1, 3703 f 1and apertures 3703 d 2, 3703 e 2, 3703 g 2. The combination of the gooseneck shape and the alternating lands and apertures provides hoop stressrelief to account for differences in expansion coefficients between theelement and the carrier plate/perimeter gripping portion.

FIG. 37(H) depicts an element comprising a first substrate 3612 h and asecond substrate 3602 h held in spaced-apart relationship with respectto one another via a primary seal material 3678 h within a carrier plate3601 h and perimeter gripping portion 3603 h. In this embodiment, theperimeter gripping portion comprises a compressible material that issandwiched between the element and an outer part of the carrier plate toallow for the variations in expansion coefficients between the elementand the carrier plate/perimeter gripping portion.

FIG. 37(I) depicts an element comprising a first substrate 3712 i and asecond substrate 3702 i held in spaced-apart relationship with respectto one another via a primary seal material 3778 i within a carrier plate3701 i and perimeter gripping portion 3703 i. In this embodiment, theperimeter gripping portion comprises a compressible material 3704 i thatis sandwiched between the carrier plate and the perimeter grippingportion to allow for the variations in expansion coefficients betweenthe element and the carrier plate/perimeter gripping portion.

FIG. 37(J) depicts a carrier plate 3701 j having a swivel portion 3701 j1 for pivotally attaching a perimeter gripping portion 3703 j. The factthat the perimeter gripping portion is allowed to Opivot about theswivel portion accounts for variations in expansion coefficients betweenthe element and the carrier plate/perimeter gripping portion.

FIG. 37(K) depicts a carrier plate 3701 k having a perimeter grippingportion 3703 k. The perimeter gripping portion is preferably molded suchthat it is tilted toward an associated element (not shown). Acompression material 3704 k is provided to account for variations inexpansion coefficients between the element and the carrierplate/perimeter gripping portion.

FIG. 37(L) depicts a carrier plate 3701 l having a perimeter grippingportion 3703 l. The perimeter gripping portion is preferably molded suchthat it is tilted toward an associated element (not shown). A series ofvertically extending compression elements 3704 l is provided to accountfor variations in expansion coefficients between the element and thecarrier plate/perimeter gripping portion.

FIG. 37(M) depicts a carrier plate 3701 m having a perimeter grippingportion 3703 m. The perimeter gripping portion is preferably molded suchthat it is tilted toward an associated element (not shown). A series ofhorizontally extending compression elements 3704 m is provided toaccount for variations in expansion coefficients between the element andthe carrier plate/perimeter gripping portion.

Turning now to FIGS. 38(A-C), an element 3812 a is depicted proximate analignment plate 3801 a, 3801 b and an electrical circuit board 3820 a,3820 b. In at least one embodiment, an electrical clip 3884 a, 3884 bhaving a contact post 3886 a, 3886 c is connected to an elementelectrical connection 3885 a, 3885 b. The element electrical connectionmay be via an electrically conductive epoxy, solder, conductive adhesiveor an edge spring clip. When the element is engaged with the electricalcircuit board, the contact post is received through a hole 3821 a, 3821c in the electrical circuit board and is slidingly engaged with frictionfit contacts 3822 a, 3822 c, 3823 a, 3823 c. FIG. 38C depicts anenlarged view of the corresponding area 3827 b of FIG. 38B. In at leastone embodiment, the alignment plate comprises apertures 3803 a, 3804 afor alignment with apertures 3824 b, 3825 b, respectively, of theelectrical circuit board. Preferably, alignment pins (not shown) areprovided elsewhere in the associated mirror assembly, such as, in thehousing or bezel to accurately position the individual components withinthe assembly. In at least one embodiment, the alignment plate comprisesan aperture 3802 a through which the contact post is received foralignment with the corresponding hole in the circuit board. In at leastone embodiment, the alignment plate comprises features 3805 a, 3805 b,3806 a, 3806 b for accurately securing the components within a completeassembly. It should be understood that the electrical circuit board maycomprise components such as a microprocessor and/or other electricalcomponents, such as a display driver, a compass sensor, a temperaturesensor, a moisture detection system, an exterior light control systemand operator interfaces that are at least partially shared with at leastone mirror element dimming circuitry.

Considerations of Aesthetic Appearance and Styling.

The aesthetics of the rearview mirror assembly is not a tangible conceptand is generally guided by customer preference. Addressing theaesthetics concerns, however, is not a trivial task that often involvesbalancing of design and functionality of the resulting embodiments.

The styling and appearance of a bezel of an embodiment of the inventionmay be improved using various techniques. FIG. 39, for example,illustrates the use of a bezel 3944, which has at least one metallicsurface, e.g., a portion of the bezel made of chromium or plastic orother material that is chromium-plated. Thus, at least a portion of thefront surface of the bezel 3944 would not have a black color, but ratherwould be reflective similar to the appearance of the mirror itself andthus be difficult to distinguish from the remainder of the mirrorsubassembly. Bezel 3944 may engage a carrier plate 3945 in anyconventional manner.

Another reason why the bezels typically are fairly wide is toaccommodate the difference in the coefficient of thermal expansion ofthe material from which the bezel is made relative to the materials usedto form the electrochromic element. Conventional bezels are made out ofstrong and fairly rigid engineering plastics such as polypropylene,ABS/PC, ASA, and have thermal expansion coefficients that are muchlarger than glass mirrors. This expansion difference can createtremendous hoop stress as the strong rigid bezel shrinks around themirror at cold temperatures. As a result, conventional bezels may haveribs or defined voids for accommodating the thermal expansion differencebetween the element and rigid bezel. A solution in this regard isillustrated in FIG. 40 in which the bezel 4044 a is formed of anelastomeric material which stretches and contracts with the thermalexpansion/contraction of the electrochromic element.

The elastomeric material could be injected or resin transfer moldeddirectly around the mirror element such as with injection molded PVC orpolyurethane Reactive Injection Molding (RIM). The elastomeric bezelcould be injection molded separately out of elastomeric materials knownas Thermoplastic Elastomers (TPE) such as thermoplastic polyurethane(TPU), thermal plastic polyolefin (TPO, TPV), Styrenic ThermoplasticElastomer (TPS), Polyester Thermoplastic Elastomer (TPC), Nylon orPolyamide Thermoplastic Elastomer (TPA) or a vulcanized or polymerizedrubber, polyurethane, silicone or fluoroelastomer and then applied tothe mirror element. One approach would be to injection mold theelastomeric bezel in a “C” or “U” shape that is the mirror shape andsize or preferably that is slightly smaller than the mirror shape andsize and then stretch and “snap” the bezel onto the mirror. Bezels madein such a fashion fit snugly on the mirror and survive thermal shock andthermal cycling very well. One benefit of “C” or “U” shaped bezels is ifthey are made symmetrical from front to back, a bezel that is made forthe drivers side of the vehicle, if rotated 180 degrees, will generallyalso fit the passenger side of the vehicle because the two mirrors areusually mirror images of one another. Since the bezels are flexible,another benefit is that a bezel made for a flat mirror will also conformto a convex or aspheric mirror shape. Only one bezel needs to be tooledto fit the left and right side flat, convex and aspheric mirrorsresulting in major cost, time and inventory savings. It may be desirableto fix or fasten the bezel to the mirror or mirror back with adhesive ormechanically to avoid the bezel dislodging from the mirror if the mirroris scraped with an ice scraper. The adhesive could be a single componentsystem such as a moisture cure silicone or urethane that is appliedeither around the edge on the glass or inside the “C” or “U” shapedbezel or both. The bezel could then be applied and the adhesive wouldcure with time. A two component or solvent-based adhesive could also beused in this manner. A hot melt adhesive could also be applied to theperimeter of the mirror or inside the “C” or “U” of the bezel or both.The bezel could then be applied to the mirror while the adhesive wasstill hot or the bezel/mirror assembly could be re-heated to melt thehot melt and bond the bezel to the mirror. A mechanical means to trap orengage the elastomeric bezel in place could also be used. The bezelcould be made with holes or grooves in the back or side to engage with amore rigid back member. The elastomeric bezel could also be co-injectedwith a more rigid material that would form an elastomeric portion aroundthe perimeter and a more rigid section around the back of the mirror tohold the elastomeric section in place. This rigid section could covermost of the back of the mirror and engage with the power pack oradjustable mirror support that holds the mirror in place in the mirrorhousing shell. The mirror in this arrangement could be attached to therigid back portion with adhesive or double sided adhesive tape. Therigid portion could also only cover the perimeter of the mirror back andattach to a carrier that engages with the power pack or adjustablemirror support. In any case, the rigid portion of the mirror back wouldmechanically hold the elastomeric portion of the mirror back and bezelin place. An adhesive could also be used to bond the elastomeric portionof the bezel or mirror back to the more rigid portion of the mirror backto hold it in place.

FIG. 41 plots Force vs. Displacement for short sections cut from atypical bezel made from different materials. The short sections werefixtured in a Chatillon (Greensboro, N.C.) device and pulled. The forcevs. displacement plots show that with rigid materials typically used tomake prior art bezels (Geloy, ASA/PC) the force increases rapidly with asmall change in displacement when compared to bezels made fromelastomers or rubbers (950 U, DP7 1050, RPT). Consequently, bezels madeof these elastomeric materials that snugly fit the glass mirror at roomtemperature do not generate high values of hoop stress as the bezelcontracts around the glass at low temperatures. By contrast, a bezelmade of a rigid material like ASA/PC that fit snugly at room temperaturewould generate high values of hoop stress as the bezel contracts aroundthe glass at low temperatures. The elastomeric bezel 4044 a ispreferably disposed around the periphery of at least the front element612. Due to its elastic nature, the elastomeric bezel has a smallerperimeter than that of at least the front element so that theelastomeric bezel fits snugly around the mirror element.

Some of the physical properties of rigid and elastomeric bezel materialsare shown below in Table 5. The tensile modulus of some prior art rigidplastic material range for a low of 72,000 psi to a high of just over350,000 psi. By contrast, the preferred elastomeric bezel materials havea tensile modulus of from about 100 psi to 3,000 psi. Thus, theinventive elastomeric bezel materials have a tensile modulus of lessthan about 72,000 psi, and may have a tensile modulus less than about3,000 psi. The lower the tensile modulus of the bezel material, thelower the hoop stress value will be in the thermal coefficientmismatched system of a glass mirror surrounded by a plastic bezel.

TABLE 5 Tensile Tensile Tensile Tensile Modulus Elongation, Elongation,Strength, Glass Transition Shore Hardness polymer (100% Secant) psibreak (%) yield (%) yield (psi) Temperature (° F.) (R = Rockwell R)Bayer T84 PC/ABS 336000  75 4 8000 N/A 119R GE LG9000 PC/ABS 352000  75N/A 7900 N/A 118R GE Geloy PC/ASA 324000  25 4-5** 8600 N/A 114RHuntsman AP 6112-HS PP 72500-1100000  120* 6 3550 N/A 98R Bayer Makrolon3258 PC 348000 125 6 9100 N/A ~115R*** Texin DP7-1050 polyether 1100(100%) 450 N/A 5000 −47 90A Texin 950 U polyether 2000 (100%) 400 N/A6000 −17 50D (~93A) Multibase Inc. Multi-Flex A 3810  170 (100%) N/A700  725 N/A 45A TPE Multibase Inc. Multi-Flex A 4001  120 (100%) 600N/A 800 N/A 33A LC TPE Multibase Inc. Multi-Flex A 4710 S  175 (100%)700 N/A 750 N/A 49A TPE DSM Sarlink 4139D TPE 1550 (100%) 588 N/A 2340N/A 39D (~88A) *Value taken from “Machinery's Handbook 25” **Data takenfrom www.matweb.com ***Data taken from Hardness Comparison Chart

Methods for connecting electrodes of an electrochromic medium to aheater circuit or a flexible circuit board are disclosed in commonlyassigned U.S. Pat. No. 6,657,767, the entire disclosure of which isincorporated herein by reference. Specifically, part of the flexiblecircuit board on which the heater circuit is provided may extend beyondthe edges of element 614 and wrap upwardly so as to make contact withconductive material on the edge of the electrochromic device.

Another option for providing electrical contact in an embodiment (notshown) including both a conductive material 852 in the seal region and abezel such as the bezel 3944, 4044 a embracing an edge portion of theembodiment would be to dispose a conductive layer or other material onthe inner surface of the bezel 3944, 4044 a, in which case pressureexerted by the bezel would create the contact force between theconnector and either the electrode layers themselves or the conductiveportion 852 of the seal.

As apparent from the foregoing embodiments, portions of the seal may beconfigured to function as an electrical bus. The seal may beelectrically conductive either across a portion of its width, a portionof its height, or a portion of its length. A seal may be formed of aconductive ink or epoxy and may be filled with metal flakes, fibers,particles, or other conductive materials as described above.

It should be noted that the zero offset mirror with either the majorityof the seal between the substrates or on the edge of the substratespresents a very sleek profile as compared to a typical electrochromicmirror with an offset and may require no substantial bezel at all. Forexample, with a black or tinted seal between the substrates anaesthetically pleasing mirror can be made by just rolling black ortinted paint over the edges of the mirror. The bezel would then consistof just a thin layer coating of paint or other material on the perimeterof the mirror that would look like a bezel. Likewise, this thin coatingcan be applied to wrap over the edge and cover a portion, or all, of theregion between the substrate seal. This process would also apply tomirrors where the majority of the seal is on the edge of the glass. Athin coating of paint or other material could be applied to the edge ofthe mirror to present an edge that is aesthetically pleasing and uniformin appearance. Further, by providing a wider and more uniform seal, theneed to obscure the seal may be eliminated.

With respect to various embodiments discussed above, as will be apparentto those skilled in the art, each of the embodiments is advantageous inthat the vertical positional offset between the front and rear elements612 and 614 may be reduced or eliminated thereby reducing anycorresponding portion of the width of the bezel (if provided). Otheraspects of the invention can otherwise be used to obscure the view ofthe seal or provide unique bezels. It will be appreciated, however, thatthe various aspects may be used separately regardless of implementationof any of the other aspects, or may be used in various combinations.

As noted above, FIGS. 34-42 are enlarged fragmentary cross sectionalviews of the edge of eleven additional mirror constructions, each havinga bezel aesthetically covering an outboard edge of an electrochromicmirror element, the bezels in FIG. 34-36B being bonded to an edge of acarrier of the mirror subassembly, and the bezels in FIGS. 37-42 beingmechanically interlockingly engaged (and also potentially bonded) withan edge of a carrier in FIGS. 37-42.

In the FIGS. 34-49, similar and identical components are referred tousing the same numbers, but with the addition of a letter (e.g. “A”,“B”, etc.). This is done to reduce redundant discussion.

More specifically, in FIGS. 34-42, the electrochromic mirror subassembly4210 includes front and rear glass mirror elements 4212 and 4214defining a cavity 4225 therebetween filled with electrochromic material4226. Electrodes, clips, a seal, a reflective layer, and other structureare included as described above and as shown in previously describedFigures. The illustrated elements 4212 and 4214 have edges thatpreferably have a “zero offset” (i.e. the edges are on average about1-mm or less from perfect alignment, or more preferably are about 0.5-mmor less from perfect alignment, or most preferably are about 0.2-mm orless from perfect alignment). It is noted that illustrated mirrors havea zero offset that extends completely around their periphery, however,it is conceivable that some bezels could function where the zero offsetextends along only part of the edges of the front and rear elementassemblies.

The mirror assembly 4208 (FIG. 42) includes a carrier 4260 with asubstantially flat front surface 4261, and further includes asubstantially flat thin heater element 4262 and double-sticky-sided foamtape 4263 that adheringly bond the electrochromic mirror subassembly4210 to the front surface 4261 in a laminar well-supported arrangement.The front surface 4261 of the carrier 4260 is made to be as flat aspossible so that the front and rear elements 4212 and 4214 do notundergo localized deformation that would unacceptably distort reflectedimages. Depending on the flatness of the front surface 4261, the frontand rear elements 4212 and 4214 are made thicker or thinner. It iscontemplated that the carrier 4260 may be a molded plastic component, ormay be a metal or other material. If the reader desires additionalinformation on such systems, the reader's attention is directed to U.S.Pat. Nos. 6,195,194 and 7,287,868, the entire contents of both of whichare incorporated herein in their entirety.

A bezel 4244 (FIG. 42) is attached to the mirror assembly 4208. Thebezel 4244 has a C-shaped cross section, and forms a continuous loopthat extends around a perimeter of the mirror subassembly 4210 in afashion similar to bezels 544 of FIG. 5. The bezel 4244 (FIG. 42)includes a forwardly-extending leg 4265, a front lip 4266 that extendsonto an outer marginal portion of the front surface 4212 a of the frontelement 4212, and a rear lip 4267 that extends onto an outer marginalportion of the rear surface 4268 of the carrier 4260. As illustrated inFIG. 42, an edge flange 4269 on the carrier 4260 forms a rear-facingrecess 4270 that receives the rear lip 4267. The inner surface of theleg 4265 closely engages the edges of the front and rear elements 4212and 4214, and the inner surface of the lips 4266 and 4267 closely engagethe front surface 4212 a of front element 4212 and the rear surface 4268of the carrier 4260, respectively. In a preferred embodiment, the bezel4244 is insert molded onto the carrier 4260, with the rear lip 4267being bonded to the rear surface 4268 of the carrier 4260 as part of themolding process. Alternatively, the rear lip 4267 can be adhered orbonded as a secondary assembly process. It is contemplated that thefront lip 4266 can also be bonded to the front surface 4212 a of thefront element 4212. The leg 4265 could also be bonded to an edge of thefront and rear elements 4212 and 4214, although this is not a requiredor condition. Alternatively, it is contemplated that the front lip 4266can be formed with an “over-bent” condition so that the innermost tip4266′ of the front lip 4266 resiliently engages the front surface 4212 awith a bias, and is not held away by engagement of an outboard portionof the front lip 4266. By this arrangement, the bezel 4244 is anintegral part of the mirror assembly 4208, and both helps retain theassembly together, and also seals an outer edge of the electrochromicmirror subassembly 4210.

The bezel 4244 has an exceptionally thin profile dimension 4271. This isa desirable condition which original equipment manufacturers are lookingfor, in order to allow a smaller dimension 4272 to the inner surface4283 of the outside rearview mirror housing 4273. This is an importantcharacteristic to original equipment manufacturers of vehicles, sincelarger mirror subassemblies 4210 allow greater fields of vision in arearward direction, and smaller exterior mirror housings 4273 allowgreater field of vision in a forward direction (i.e. past the mirrortoward a front of the vehicle). It is contemplated that the material ofbezel 4244 can be elastomer or a more rigid thermoplastic or metalmaterial, as described above in regard to bezel 4044 a (FIG. 40). It iscontemplated that the front lip 4266 will be about 2-mm wide or less,and will cover a continuous perimeter strip on the front surface 4212 athat is about 2-mm or less wide. However, it is contemplated that thelip 4266 can cover a strip on the front surface that is as low as about1-mm or less wide; or can be made to extend onto the front surface 4212a only in certain areas (such as top and bottom edges and not onto theright and left sides of the face surface 4212 a); or can be made to notextend onto the front surface 4212 a at all. Where the bezel does notcover any of the elements 4212 and 4214, the entire front surface of thefront element 4212 can be used (i.e. 100% of the front surface can beused for showing a reflected image). This is believed to be novel andnon-obvious for modern mirrors with electronic options, especiallyelectrochromic mirrors. (See, e.g., embodiments of FIGS. 6(A), 8(D), 12,14-16, 24, 25, 27-29, 30B-34, 49 and 57.)

Bezel 4244A (FIG. 43) is similar to the bezel 4244 (FIG. 42), exceptthat the recess 4270A is formed on a front surface of the carrier 4260A,and the rear lip 4267A is positioned in and bonded to the front surfaceof the carrier 4260A. As a result, the rear lip 4267A is positioned in aspace 4263A′ located between the edge of the carrier 4260A and the edgeof the rear element 4214. The rear lip 4267A terminates outboard of anouter edge of the heater 4262 and the foam tape 4263.

Bezel 4244A′ (FIG. 43A) is similar to bezel 4244A, except in bezel4244A′, the carrier 4260A′ has a forwardly extending lip 4260A1 thatengages a mating recess 4260A2 in a rear of the bezel's rear lip 4267A′.Also, the carrier 4260A′ is modified to include an aperture 4260A3permitting wire 4260A4 to pass through and connect to the electricalconductor or clip 4260A5 for operating the electrochromic material4226A.

Bezel 4244B (FIG. 44) is similar to the bezel 4244A (FIG. 43), with therecess 4270B being formed on a front surface of the carrier 4260B.However, the front surface of the rear lip 4267B of bezel 4244B iscoplanar with the front surface of the carrier 4260B, and the outer edgeof the foam tape 4263 (and also the heater 4262) extends onto the rearlip 4267B.

Bezel 4244C (FIG. 37) is similar to the bezel 4244 (FIG. 34) except thatthe carrier 4260C includes a trapezoidally-shaped keyhole 4275C, and thebezel 4244C includes a key 4276C that engages the keyhole 4275C topositively mechanically retain the bezel 4244C to the mirror assembly4208. It is contemplated that the key 4276C is molded as part of theinsert molding process of molding the bezel 4244C onto the mirrorassembly 4208. However, the keyed arrangement can also be made by heatstaking, or by sonic or mechanical methods of forming a protrusion intothe shape of a key or rivet-like connection.

Bezel 4244D (FIG. 46) is similar to the bezel 4244C (FIG. 45), exceptthat the keyhole 4275D faces an opposite direction (i.e. a large endopens rearwardly), and the key 4276D extends into the keyhole 4275D froma front location.

Bezel 4244E (FIG. 47) is similar to the bezel 4244D, with the key 4276Eextending rearwardly. In bezel 4244E, the tape 4263 extends onto therear lip 4267E. However, the key 4276E is preferably located at oroutboard of an outboard edge of the foam tape 4263, to minimize apossibility of the key 4276E disrupting the surface that the tape 4263is bonded to; however, this is not required.

Bezel 4244F (FIG. 48) is similar to the bezel 4244C (FIG. 45), exceptthat bezel 4244F of FIG. 48 includes a large radius 4277F on an insidecorner of defined by the joint of leg 4265F and front lip 4266F. Thelarger radius 4277F forms a cavity that better assures that the insidecorner does not engage an edge of the front element 4212 in a mannercausing the front lip 4266F to stand away from the front surface 4212 a.The radius 4277F also causes a thinned section on a front portion 4278Fof leg 4265F that both acts as a resilient hinge point and preventsbending in other undesirable areas along leg 4265F.

Bezel 4244G (FIG. 49) is similar to bezel 4244F of FIG. 48, except thatbezel 4244G includes a second large radius 4279G at the corner formed bythe leg 4265G and the rear lip 4267G. This allows the leg 4265G (andfront lip 4266G) to adjust to any undulations along the edge of themirror assembly 4208G, such as may occur along a clip positioned on theedge of the mirror subassembly 4210G.

Bezel 4244H (FIG. 50) is similar to the bezel 4244G (FIG. 449), exceptthat the front-located radius 4277H is made larger than front radius4277G. Further, the radius 4277H is also shifted so that, instead ofbeing at the corner, the radius 4277H is located on the underside of thefront lip 366H.

As noted above, the FIGS. 51-54 are enlarged fragmentary cross sectionalviews of the edge of four additional mirror constructions, each having abezel aesthetically covering a front edge of an electrochromic mirrorelement, the bezels in FIGS. 51-52 also covering an entire side of theedge, but the bezels in FIGS. 53-54 only partially covering a side ofthe edge.

More specifically, the bezel 4244I (FIG. 51) is L-shaped and includes aleg 4265I and front lip 4266I, but does not include a rear lip 4267. Theleg 4265I is spaced slightly away from the edge of the front and rearelements 4212 and 4214, creating a gap 42791. Preferably, the front lip42661 is insert molded onto and bonded to the front surface 4212 a. Thegap 4279I prevents any irregularity along the edge of the front and rearelements 4212 and 4214 from deforming the leg 4265I of the bezel 4244Iin a manner that reads through onto the front lip 4266I. Also, the gap4279I allows the leg 4265I to flex and move when the elements 4212/4214and the bezel 4244I undergo different thermal expansions/contractions.Bezel 4244J (FIG. 52) is similar to bezel 4244I (FIG. 5I), except thatbezel 4244J does not include any gap (4279I) between leg 4265J and theedges of the front and rear elements 4212 and 4214. If desired, leg4265J is bonded to the side edges of the elements 4212 and 4214.

Bezel 4244K (FIG. 53) is similar to bezel 4244I (FIG. 41), except thatthe leg 4265K is shortened, such that it extends only slightly past thecavity 4225. Further, the end 4280K of the leg 4265K is tapered towardthe rear element 4214. The bezel 4244L (FIG. 54) is similar to bezel4244J (FIG. 52), but bezel 4244L (FIG. 54) includes an end 4280L thatterminates short of the cavity 4225, and that is relatively blunt ratherthan being tapered. Specifically, the end 4280L terminates on an edge ofthe front element 4212. The end 4280L can be bonded to a side edge ofthe element 4212 as part of an insert molding operation, for example.

FIGS. 55-57 are enlarged fragmentary cross sectional views of the edgeof three additional mirror constructions, each having an edge of anelectrochromic mirror element coated by a strip of material. Thesearrangements are described as bezels since they provide a similarappearance, including a thin profile around a perimeter of the mirrorsubassembly 4210.

Bezel 4244M (FIG. 55) is similar to bezel 4244J, in that it includes anL-shaped strip of material with a front lip 4266M extending on the frontsurface and a leg 4265M extending across side edges of the front andrear elements 4212 and 4214. The material of bezel 4244M and examples ofthe process of applying the bezel 4244M are described above in regard toFIGS. 14-16(B). (For example, see coating 1676, FIG. 16(A), and seenon-conductive material 1262, FIG. 12, and see elastomeric material 4044a, FIG. 40.)

Bezel 4244N (FIG. 56) is similar to bezel 4244M (and bezel 4244L) inthat the bezel 4244N includes a front lip 4266N and leg 4265N. However,the leg 4265N is shortened such that it extends short of the cavity4225.

Bezel 4244P (FIG. 57) is similar to the bezels 4244M and 4244N, in thatit includes a painted strip of material located along a marginal edge ofthe front element 4212. However, bezel 4244P is applied to the secondsurface of the front element 4212 (i.e. in the cavity 4225) and does notextend onto side edges of the front or rear elements 4212 and 4214.Visually, the appearance is not unlike the bezel 4244M (FIG. 55) andbezel 4244N (FIG. 56). The material of bezel 4244P can be opaque,translucent, light-absorbing, or reflective, and dark or light color.

FIGS. 58-59 are enlarged fragmentary cross sectional views of bezelshaving a C-shaped cross section that covers a side edge of theelectrochromic mirror element and that wraps onto the first and fourthsurfaces of the electrochromic mirror element subassembly. However, thebezels further include a resiliently flexible fin that extends laterallyaway from the electrochromic mirror element into wiping contact with amirror housing.

More specifically, the bezel 4244Q (FIG. 59) is C-shaped, and is notunlike the bezel 544 (FIG. 5), or bezel 4044 a (FIG. 40) or bezel 4244(FIG. 42). The bezel 4244Q includes a leg 4265Q creating a gap 4279Q toan edge of the front and rear elements 4212 and 4214, and furtherincludes a front lip 4266Q that extends onto the front surface 4212 a ofthe front element 4221, and a rear lip 4267Q that extends onto a rearsurface 4214 b of the rear element 4214. A flexible resilient fin 4282Qextends in a outboard direction from a midpoint on the leg 4265Q. Theillustrated fin 4282Q becomes thinner and thinner as it extends to itstip, although it is contemplated that the fin can have different shapes.The mirror housing 4273 includes an inner surface 4283Q that is engagedby the fin 4282Q. It is preferable that the fin 4282Q only lightlyengage the inner surface 4283Q so that minimal frictional drag iscreated as the mirror assembly 4208 is angularly adjusted within themirror housing 4273. Thus, the power pack that is connected to thecarrier 4260Q and that angularly adjusts the mirror assembly maintainsits low energy requirement for adjustment. It is noted that the fin4282Q can be designed to allow a small gap to occur between the fin4282Q and the inner surface 4283Q, especially at extreme angularpositions of the mirror assembly if desired. The fin 4282Q allows thevertical and horizontal dimensions of the mirror subassembly 4210 to bemaximized relative to the opening 4284Q defined by the housing 4273.This is an important characteristic to original equipment manufacturersof vehicles, since larger mirror subassemblies 4210 allow greater fieldsof vision in a rearward direction, and smaller exterior mirror housings4273 allow greater field of vision in a forward direction.

Bezel 4244R (FIG. 59) is similar to bezel 4244Q, except bezel 4244Rincludes a foreshortened leg 4265R and a front lip 4266R similar to thebezel 4244L (FIG. 54). A resilient fin 4282R extends laterally from theleg 4265R in an outboard direction, into light sliding contact with theinner surface 4283R of the housing 4273.

It is contemplated that the bezels 4244-4244R can be extruded onto ormolded onto or adhering applied to the front surface 4212 a of a frontelement 4212; and/or extruded or molded or applied onto the front andside surfaces of the mirror subassembly 4210 (which includes elements4212 and 4214); and/or extruded/molded/applied onto the mirrorsubassembly 4210 (which includes elements 4212, 4214, carrier 4260,heater 4262, and foam tape 4263); and/or extruded/molded/applied to thecarrier 4260; and/or extruded/molded/applied to the side edges of one orboth of the elements 4212, 4214. For example, technology is available toextrude polymer directly onto a window glass. See Osanami U.S. Pat. No.5,158,638, issued Oct. 27, 1992, entitled METHOD OF MAKING WINDOW GLASSWITH A GASKET, the entire contents of which are incorporated herein byreference for the purpose of teaching such a method of directapplication/extruding onto a glass element.

Examples of Embodiments Including a Light Source and Other OpticalElements.

Turning now to FIGS. 60-61, a carrier 4260 with an integral bezel 4266on only the “inboard edge” is depicted. This carrier with integral bezelis preferred for use with elements as described with regard to FIGS.6(B), 21(A) and 21(B). A related assembly method is to provide a doublesided adhesive layer, such as a tape or foam, and adhere an element tothe carrier with integral bezel such that the related contacts to theassociated electrically conductive layers are disposed within the bezelreceptacle 4266 a. Most preferably, the bezel is positioned on an edgeof the element to be located closest to the associated vehicle (i.e. theinboard edge).

It is contemplated that the present inventive concepts can be used incombination with mirrors (interior and/or exterior) having manydifferent options to create synergistic and non-obvious combinationsthat provide surprising and unexpected benefits not previously possible.For example, turning now to FIG. 62, an interior mirror assembly 6200includes a bezel 6255 (similar to any of bezels 544 of FIG. 5 and/or4244-4244R in FIGS. 42-59) and a case 6256. The bezel and the casecombine to define a mirror housing for incorporation of features inaddition to a reflective element and information displays. Commonlyassigned U.S. Pat. Nos. 6,102,546; D 410,607; 6,407,468; 6,420,800; andU.S. patent application Ser. No. 09/687,743, the disclosures of whichare incorporated in their entireties herein by reference, describevarious bezels, cases, and associated button constructions for use withthe present invention.

With further reference to FIG. 62, mirror assembly 6200 includes firstand second illumination assemblies 6267, 6271. Various illuminationassemblies and illuminators for use with the present invention aredescribed in commonly assigned U.S. Pat. Nos. 5,803,579, 6,335,548, and6,521,916, the disclosures of which are incorporated in their entiretiesherein by reference. As further depicted in FIG. 64, each illuminationassembly preferably comprises a reflector, a lens, and an illuminator(not shown). Most preferably there are two illumination assemblies withone generally positioned to illuminate a front passenger seat area andthe second generally positioned to illuminate a driver seat area. Theremay be only one or may be additional illuminator assemblies such as oneto illuminate a center console area, overhead console area, or an areabetween the front seats.

With further reference to FIG. 62, mirror assembly 6200 includes firstand second switches 6275, 6277. Suitable switches for use with thepresent invention are described in detail in commonly assigned U.S. Pat.Nos. 6,407,468 and 6,420,800, 6,471,362, 6,614,579, the disclosures ofwhich are incorporated in their entireties herein by reference. Theseswitches may be incorporated to control the illumination assemblies, thedisplays, the mirror reflectivity, a voice-activated system, a compasssystem, a telephone system, a highway toll booth interface, a telemetrysystem, a headlight controller, a rain sensor, etc. Any other display orsystem described herein or within the reference incorporated byreference may be incorporated in any location within the associatedvehicle and may be controlled using the switches.

With further reference to FIG. 62, mirror assembly 6200 includesindicators 6283. Various indicators for use with the present inventionare described in commonly assigned U.S. Pat. Nos. 5,803,579, 6,335,548,and 6,521,916, the disclosures of which are incorporated in theirentireties herein by reference. These indicators may indicate the statusof the displays, the mirror reflectivity, a voice-activated system, acompass system, a telephone system, a highway toll booth interface, atelemetry system, a headlight controller, a rain sensor, etc. Any otherdisplay or system described herein or within the references incorporatedby reference may be incorporated in any location within the associatedvehicle and may have a status depicted by the indicators.

With further reference to FIG. 62, mirror assembly 6200 includes firstand second light sensors 6286, 6288. Preferred light sensors for usewithin the present invention are described in detail in commonlyassigned U.S. Pat. Nos. 5,923,027 and 6,313,457, the disclosures ofwhich are incorporated in their entireties herein by reference. Theglare sensor and/or ambient sensor automatically control thereflectivity of a self-dimming reflective element as well as theintensity of information displays and/or backlighting. The glare sensoris used to sense headlights of trailing vehicles and the ambient sensoris used to detect the ambient lighting conditions that the system isoperating within. In another embodiment, a sky sensor may beincorporated positioned to detect light levels generally above and infront of an associated vehicle, the sky sensor may be used toautomatically control the reflectivity of a self-dimming element, theexterior lights of a controlled vehicle and/or the intensity ofinformation displays.

With further reference to FIG. 62, mirror assembly 6200 includes first,second, third, and fourth operator interfaces 6290, 6291, 6292, 6293located in mirror bezel 6255. Each operator interface is shown tocomprise a backlit information display “A”, “AB”, “A1” and “12”. Itshould be understood that these operator interfaces can be incorporatedanywhere in the associated vehicle, for example, in the mirror case,accessory module, instrument panel, overhead console, dashboard, seats,center console, etc. Suitable switch construction is described in detailin commonly assigned U.S. Pat. Nos. 6,407,468, 6,420,800, 6,471,362, and6,614,579, the disclosures of which are incorporated in their entiretiesherein by reference. These operator interfaces may control theillumination assemblies, the displays, the mirror reflectivity, avoice-activated system, a compass system, a telephone system, a highwaytoll booth interface, a telemetry system, a headlight controller, a rainsensor, etc. Any other display or system described herein or within thereferences incorporated by reference may be incorporated in any locationwithin the associated vehicle and may be controlled using an operatorinterface or interfaces. For example, a user may program a display ordisplays to depict predetermined information or may program a display ordisplays to scroll through a series of information, or may enter setpoints associated with certain operating equipment with associatedsensor inputs to display certain information upon the occurrence of agiven event. In one embodiment, for example, a given display may be in anon-illuminated state until the engine temperature is above a threshold,the display then automatically is set to display the engine temperature.Another example is that proximity sensors located on the rear of avehicle may be connected to a controller and combined with a display ina rearview mirror to indicate to a driver the distance to an object; thedisplay may be configured as a bar that has a length proportional to thegiven distance. In addition to or instead of the above-mentioneddevices, fewer or more individual devices may be incorporated in anylocation within the associated vehicle and as described within thereferences incorporated herein.

Turning now to FIG. 63, there is shown a section view of the mirrorassembly 6300 that includes the embodiment 6200 of FIG. 62, with areflective electrochromic mirror subassembly 6305 affixed to an internalplate frame 6321 with double-sided adhesive foam tape 622. An attachmentcomponent 6334 is screwed to (or integrally formed from) plate frame6321 and defines a ball section 6324 that engages a crown section 6372in the two-ball mount 6357 with tube assembly 6357′. The depictedsections of FIG. 63 are taken along a cut line VI-VI of FIG. 62. FIG. 63shows a preferred positional relationship of information displays 6326and/or backlighting (not specifically shown located at a bottom of themirror subassembly 6325) with respect to reflective element 6305 withina housing defined by case 6356 and bezel 6255. In further reference toFIGS. 62 and 63, the mirror assembly 6300 is also shown to comprise amicrophone 6259; first operator interface 6290 along with circuit board6395; mirror mount 6357 and accessory module 6358. The mirror mount 6357and/or an accessory module 6358 may comprise compass sensors, a camera,a headlight control, an additional microprocessor, a rain sensor,additional information displays, additional operator interfaces, etc.

Turning now to FIG. 64, there is shown an exploded view 6400 of themirror assembly 6300. FIG. 64 provides additional details with regard toone preferred positional relationship of individual components, as wellas providing additional structural detail of a mirror assembly. Asshown, the mirror assembly comprises a reflective element 6405 within abezel 6455 and a mirror case 6456. Bezel 6455 can be adapted to be likeany of bezels 1944 and 4244-4244R previously described. A mirror mount6457 is included for mounting the mirror assembly within a vehicle. Itis noted that a person skilled in the art of vehicle mirror design canre-design the bezel 6455, mirror case 6456, and tube mount 6457 to bereplaced with the bezel 4244 (-4244R), mirror housing 4273, and carrier4260 previously described in this application. It should be understoodthat a host of accessories may be incorporated into the mount 6457and/or onto the plate frame carrier 6321 in addition to a power packadjuster, such as a rain sensor, a camera, a headlight control, anadditional microprocessor, additional information displays, compasssensors, etc. These systems may be integrated, at least in part, in acommon control with information displays and/or may share componentswith the information displays. In addition, the status of these systemsand/or the devices controlled thereby may be displayed on the associatedinformation displays.

The mirror assembly is shown in FIG. 64 to further comprise thirdinformation display 6426 with third information display backlighting6437, 6438, 6439; first and second microphones 6460, 6461; and includesother known options such as a first reflector with a first lens; asecond reflector with a second lens; a glare sensor; an ambient lightsensor; first, second, third, and fourth operator interfaces 6490, 6491,6492, 6493 with first, second, third, and fourth operator interfacebacklighting 6490 a, 6491 a, 6492 a, 6493 a; a circuit board 6495 havinga compass sensor module 6499; and a daughter board 6498 with aninput/output bus interface 6497.

Preferably, the illumination assemblies with associated light source areconstructed in accordance with the teachings of commonly assigned U.S.Pat. Nos. 5,803,579 and 6,335,548, as well as U.S. patent applicationSer. No. 09/835,278, the disclosures of which are incorporated in theirentireties herein by reference.

Preferably, the glare light sensor and the ambient light sensor areactive light sensors as described in commonly assigned U.S. Pat. Nos.6,359,274 and 6,402,328, the disclosures of which are incorporated intheir entireties herein by reference. The electrical output signal fromeither or both of the sensors may be used as inputs to a controller onthe circuit board 6440 or 6495 to control the reflectivity of reflectiveelement 6405 and/or the intensity of third information displaybacklighting. The details of various control circuits for use herewithare described in commonly assigned U.S. Pat. Nos. 5,956,012; 6,084,700;6,222,177; 6,224,716; 6,247,819; 6,249,369; 6,392,783; and 6,402,328,the disclosures of which are incorporated in their entireties herein byreference. These systems may be integrated, at least in part, in acommon control with information displays and/or may share componentswith the information displays. In addition, the status of these systemsand/or the devices controlled thereby may be displayed on the associatedinformation displays.

Although the compass sensor module 6499 is shown to be mounted circuitboard 6495 in FIG. 64, it should be understood that the sensor modulemay be located within mount 6457, an accessory module 6458 positionedproximate mirror assembly 6400 or at any location within an associatedvehicle such as under a dashboard, in an overhead console, a centerconsole, a trunk, an engine compartment, etc. Commonly assigned U.S.Pat. Nos. 6,023,229, 6,140,933, and 6,968,273 as well as commonlyassigned U.S. Patent Application 60/360,723, the disclosures of whichare incorporated in their entireties herein by reference, described indetail various compass systems for use with the present invention. Thesesystems may be integrated, at least in part, in a common control withinformation displays and/or may share components with the informationdisplays. In addition, the status of these systems and/or the devicescontrolled thereby may be displayed on the associated informationdisplays.

Daughter board 6498 is in operational communication with circuit board6495. Circuit board 6495 may comprise a controller 6496, such as amicroprocessor, and daughter board 6498 may comprise an informationdisplay. The microprocessor may, for example, receive signal(s) from thecompass sensor module 6499 and process the signal(s) and transmitsignal(s) to the daughter board to control a display to indicate thecorresponding vehicle heading. As described herein and within thereferences incorporated by reference herein, the controller may receivesignal(s) from light sensor(s), rains sensor(s) (not shown), automaticvehicle exterior light controller(s) (not shown), microphone(s), globalpositioning systems (not shown), telecommunication systems (not shown),operator interface(s), and a host of other devices, and control theinformation display(s) to provide appropriate visual indications.

Controller 6496 (or controllers) may, at least in part, control themirror reflectivity, exterior lights, rain sensor, compass, informationdisplays, windshield wipers, heater, defroster, defogger, airconditioning, telemetry systems, voice recognition systems such asdigital signal processor-based voice-actuation systems, and vehiclespeed. The controller 6496 (or controllers) may receive signals fromswitches and/or sensors associated with any of the devices describedherein and in the references incorporated by reference herein toautomatically manipulate any other device described herein or describedin the references included by reference. The controller 6496 may be, atleast in part, located outside the mirror assembly, or may comprise asecond controller elsewhere in the vehicle or additional controllersthroughout the vehicle. The individual processors may be configured tocommunicate serially, in parallel, via Bluetooth protocol, wirelesscommunication, over the vehicle bus, over a CAN bus or any othersuitable communication.

Exterior light control systems as described in commonly assigned U.S.Pat. Nos. 5,990,469; 6,008,486; 6,130,421; 6,130,448; 6,255,639;6,049,171; 5,837,994; 6,403,942; 6,281,632; 6,291,812; 6,469,739;6,399,049; 6,465,963; 6,587,573; 6,429,594; 6,379,013; 6,871,809;6,774,988 and U.S. patent application Ser. Nos. 09/847,197; and60/404,879, the disclosures of which are incorporated in theirentireties herein by reference, may be incorporated in accordance withthe present invention. These systems may be integrated, at least inpart, in a common control with information displays and/or may sharecomponents with the information displays. In addition, the status ofthese systems and/or the devices controlled thereby may be displayed onthe associated information displays.

Moisture sensors and windshield fog detector systems are described incommonly assigned U.S. Pat. Nos. 5,923,027 and 6,313,457, thedisclosures of which are incorporated in their entireties herein byreference. These systems may be integrated, at least in part, in acommon control with information displays and/or may share componentswith the information displays. In addition, the status of these systemsand/or the devices controlled thereby may be displayed on the associatedinformation displays.

Commonly assigned U.S. Pat. No. 6,262,831, the disclosure of which isincorporated herein by reference in its entirety, describes powersupplies for use with the present invention. These systems may beintegrated, at least in part, in a common control with informationdisplays and/or may share components with the information displays. Inaddition, the status of these systems and/or the devices controlledthereby may be displayed on the associated information displays.

It is contemplated that the present invention would be useful in insideor outside rearview mirrors having electro-optic mirror elements, convexmirror elements, aspheric mirror elements, planar mirror elements,non-planar mirror elements, hydrophilic mirror elements, hydrophobicmirror elements, and mirror elements having third surface and fourthsurface reflectors. It is further contemplated that the presentinvention will be useful on mirrors that are transflective, or that havea third or fourth surface mirror element with patterns of lines(sometimes referred to as “jail bars”) thereon to optimize the effect ofvisible light. Further, the present invention is useful with mirrorshaving first surface or fourth surface heaters, anti-scratch layers, andcircuit boards including flexible circuit boards, and circuit board andheater combinations, such as heaters having embedded or integratednon-heater functions such as signal ellipses and signal diffusants,locating holes or windows for light pass-through. The present inventionis also useful with potted or snap-attached or elastomeric bezels, anduseful with carriers having an ultra-flat front surface. Also,additional options can be integrated into the mirrors including signallighting, key lights, radar distance detectors, puddle lights,information displays, light sensors and indicator and warning lighting,retainers with living hinges, and integrated housings for receiving andsupporting said components. Still further, it is conceived that thepresent mirror can include a manually folding or power folding mirrors,extendable mirrors, and mirrors with a wide field of view, and withinformation on the mirror such as “object in mirror is closer than mayappear” or other indicia, such as “heated” or “auto-dim” Still further,the present invention is useful with a blue glass mirror or “bluechemical” darkening mirror. Still further, efficiencies can be had byincorporating the present concepts with mirrors having an electrochromicmirror subassembly with front and rear glass mirror elements with edgeshaving a “zero offset” (i.e. less than an average of about 1-mm, or morepreferably, less than about 0.5-mm difference between perfect alignmentof edges of the mirror elements), an edge seal, including clearreflective or opaque edge seals, and/or second surface chrome or achrome bezel.

Although the present invention has been generally described as beingused in connection with electrochromic devices, such as mirrors andarchitectural windows, those skilled in the art will understand thatvarious aspects of the present invention may be employed in theconstruction of other electro-optic devices.

Turning now to FIG. 65, there is shown an exploded view of an exteriorrearview mirror assembly 6505 having a housing 6510 connected to anattachment member 6515 via a telescoping extension 6520. In at least oneembodiment, the telescoping extension 6520 comprises a single arm havinga linear actuator for extending and retracting the telescoping extensionfrom within the associated vehicle. The telescoping extension 6520 maycomprise a rack and pinion type linear actuator, an electrical solenoidtype linear actuator, a pneumatic piston or a hydraulic actuator. Thehousing 6510 may be configured such that the housing axially pivotsabout the telescoping extension. Additionally, the telescoping extensionmay be configured such that the housing may be folded inward toward theassociated vehicle and outward away from the associated vehicle. Theattachment member 6515 is configured to be received by a vehicle mount6525. The vehicle mount may be fixed to a door panel, an A-pillar, afront fender, a window assembly, or any other position where a drivercan view the scene generally rearward of the associated vehicle. Itshould be understood that the telescoping extension may comprise two ormore arms and that the housing may be configured to pivot and foldirrespective of the number of arms employed. It should also beunderstood that the housing may be connected to a non-telescopingextension at a location shown as reference number 6520 a such that thehousing pivots about the connection 6520 a such that the mirror may bepositioned closer or farther from the vehicle as desired; this featuremay be accompanied by a power positioning mechanism such that actuationmay be performed inside the vehicle. It should be understood that themirror housing, extension and attachment member may be configured suchthat the telescoping, pivoting and folding requires a manual operation.

A wiring harness 6530 with a connector 6535 is provided to interface theexterior mirror with associated apparatus located inside the associatedvehicle. The wiring harness may be configured to provide extension,folding and pivoting of the housing and may also be configured toprovide reflective element control, electrical power, turn signalactuation, mirror heater control, mirror element positioning, lightsensor interface, exterior mirror circuit board interface, transceiverinterface, information display interface, antenna interface, lightsource power and control, emergency flasher interface, and all otherelectrical features as described herein. It should be understood thatoperator interfaces are provided within the vehicle for each of thesefeatures where appropriate.

A mirror element positioner 6540 is provided for aligning the associatedreflective element within the housing from the interior of theassociated vehicle. It should be understood that a correspondingoperator interface is provided within the vehicle for positioning of thereflective element.

The positioner 6540 is mechanically connected to a carrier for providinga secure structure for supporting and moving of the associatedreflective element. Examples of suitable carriers are described in U.S.Pat. Nos. 6,195,194 and 6,239,899, the disclosures of which areincorporated herein in their entireties by reference.

In at least one embodiment, a double sided adhesive foam 6550 isemployed to attach the reflective element to the carrier. In certaininstances, apertures 6551 may be provided in the double sided adhesivefoam for accommodating positioning of various components.

In at least one embodiment, an electrical circuit board 6555 is providedin the rearview mirror assembly. The electrical circuit board maycomprise a light source such as a turn signal light, a keyholeilluminator, or an outside door area illuminator, as taught in U.S. Pat.No. 6,441,943, the entire disclosure of which is incorporated in itsentirety herein by reference, an information display, an antenna, atransceiver, a reflective element control, an outside mirrorcommunication system, a remote keyless entry system, proximity sensors,and interfaces for other apparatus described herein. U.S. Pat. Nos.6,244,716, 6,523,976, 6,521,916, 6,441,943, 6,335,548, 6,132,072,5,803,579, 6,229,435, 6,504,142, 6,402,328, 6,379,013, and 6,359,274disclose various electrical components and electrical circuit boardsthat may be employed in one or more embodiments, the disclosures of eachof each of these U.S. patents are incorporated herein in theirentireties by reference.

In at least one embodiment, a rearview mirror assembly is provided witha heater 6560 for improving the operation of the device and for meltingfrozen precipitation that may be present. Examples of various heatersare disclosed in U.S. Pat. Nos. 5,151,824, 6,244,716, 6,426,485,6,441,943 and 6,356,376, the disclosures of each of these patents areincorporated in their entireties herein by reference.

In at least one embodiment, the reflective element is has variablereflectance feature. The variable reflectance reflective element maycomprise a first substrate 6565 and a second substrate 6570 secured in aspaced apart relationship by a seal 6575 to define a chambertherebetween. The reflective element may be configured to define aconvex element, an aspheric element, a planar element, a non-planarelement, a wide field of view element, or a combination of these variousconfigurations in different areas to define a complex mirror elementshape. The first surface of the first substrate may comprise ahydrophilic or hydrophobic coating to improve the operation. Thereflective element may comprise transflective properties such that alight source, or information display, may be positioned behind theelement and project light rays therethrough. The reflective element maycomprise an anti-scratch layer, or layers, on the exposed surfaces ofthe first and, or, second substrates. The reflective element maycomprise area(s) that are devoid of reflective material, such as etchedin bars or words, to define information display area(s). Examples ofvarious reflective elements are described in U.S. Pat. Nos. 5,682,267,5,689,370, 6,064,509, 6,062,920, 6,268,950, 6,195,194, 5,940,201,6,246,507, 6,057,956, 6,512,624, 6356,376, 6,166,848, 6,111,684,6,193,378, 6,239,898, 6,441,943, 6,037,471, 6,020,987, 5,825,5276,111,684 and 5,998,617, the disclosures of each of these patents areincorporated in their entireties herein by reference.

Modifications, Auxiliary and Alternative Embodiments.

As discussed above in reference to FIGS. 1 through 65, an embodiment ofa rearview mirror system employing an EC-element and a source of lightbehind the EC-element preferably includes a ring of an optical thin-filmspectral filter material that is circumferentially disposed in aperipheral area, next to a corresponding perimeter-defining edge, ofeither the first or the second surface of the system. It is recognizedthat the use of the peripheral ring is partly directed to configuring anoverall mirror system in such a fashion as to make the system asaesthetically appealing to the user as possible. For example, onepurpose of this thin-film ring is to hide the seal, the plug material,and, possibly, the electrical connectors of the EC-element from beingvisually discernable by the user through the first substrate. As such,this peripheral ring of material is usually opaque in at least a portionof visible spectrum of electromagnetic radiation and may be sufficientlywide, up to 6.5 mm. It has also been discussed in this application thatsuch a peripheral ring must facilitate matching of spectralcharacteristics of ambient light reflected from the periphery of themirror system that includes such a ring with those of ambient lightreflected from a central area inside the periphery of the mirror systemwhere the ring is not present. The better the spectral matching, e.g.,matching of reflectance and color gamut, the less discernable is thearea of the peripheral ring to the viewer when the EC-element isswitched “off” and the rearview assembly of the invention operatespurely as a mirror. Solutions to achieving various degrees of spectralmatching between the ring-portion of the mirror and the central,transflective portion of the mirror have already been discussed in thisapplication and included judicious thin-film designs of the peripheralring with the use of such materials as chromium, nickel, stainlesssteel, molybdenum, silicon, platinum group metals, aluminum, silver,copper, gold or various alloys of these metals.

Also discussed was another, more tangible purpose of utilizing aperipherally deposited thin-film ring—to reduce exposure of the seal,disposed between the substrates forming an EC-cavity, to UV light thatcauses degradation of the seal. Clearly, then, such UV-protectionmeasure is of particular importance in an outside rearview assembly(see, e.g., FIGS. 3 and 5) that is fully exposed to sunlight, whilerequirements to UV-properties of a ring of an EC-element employed withinan inside rearview assembly (see, e.g., FIGS. 4 and 5) may be not asstringent.

It is recognized that the use of a peripheral ring entails certainshortcomings For example, it must be realized that, in operation, theperipheral area of a mirror system of the assembly containing theperipheral ring does not darken, unlike the central portion of themirror, when the voltage is applied to the electrodes of the EC-element(or other electrically darkening technology) in order to reduce thelight-glare blinding the user. As a result, the difference inappearances of the peripheral ring and the central portion of the mirrorwhen the EC-element is “on” may be quite significant, in particular ininside rearview assemblies that typically employ higher reflectancelevels. Consequently, not only the size of the central portion of themirror is accordingly reduced, as compared to the overall front surfaceof the mirror element, by a width of the peripheral ring but theperipheral ring continues producing the undesired glare even when theEC-element is “on”. Another problem arises from the fact that a typicalmirror system of an inside rearview assembly contains an eye-hole (suchas the elements 497 and 515 of FIGS. 4 and 5) behind which correspondingsensors (such as the sensor 396 of FIG. 3) may be positioned. When theeyehole is used in combination with a peripheral ring, appropriatepositioning of the eye-hole may not be straightforward. For example, ifthe eye-hole is formed by creating an opening in a coating stack of thethird surface, then locating such an opening within the peripheral areaof the mirror element will disrupt the visual continuity of the mirrorand will be perceived as aesthetically unpleasing, particularly in anembodiment where the height of the mirror is not significant. It isappreciated that, although in description of the embodiments belowmounting elements (e.g., carrier, bezel, and housing elements) as wellas electrical connectors are omitted, all of these elements are impliedand the described alternative and modified embodiments may be used withany combination of the mounting and electrical elements discussed inthis application.

Eye-Hole Openings.

Common embodiments of automotive electrochromic mirrors generallyinclude light sensors for measuring glare and ambient light levels. Incertain embodiments the glare sensor is positioned behind the EC mirrorelement and views glare light levels through an aperture in thereflective coating. Prior art embodiments of eyehole openings for lightsensors comprise single continuous openings. These openings in thereflective layer may comprise a TCO or a transflective metal layer forconductivity. In general, these openings can be several millimeters wideand are often round or elliptical in shape. The aperture must be largeenough to allow glare light entering the vehicle to adequatelyilluminate the glare sensor for accurate light level measurement. Asingle, hard edged eyehole might be considered aesthetically less thanoptimal by certain observers. Some prior art embodiments utilize atransflective opening that is effectively stealthy and non-obvious to anobserver. For certain other embodiments discussed herein, the use of acluster of multiple, smaller openings instead one large opening may haveaesthetic and/or manufacturing advantages. Non-limiting embodiments ofmulti-opening eyeholes are shown in FIGS. 66(A-E). These examplescomprise reflective regions 6620 (reflective material present) and areas6610 that are patterned to be essentially devoid of reflective material.As shown in FIGS. 66(A-E), these patterns may be essentially circular,rectangular or line-like and may have a regular or irregular spacing. Ingeneral, an optimized pattern of reflective and essentiallynon-reflective regions within the geometric boundaries of an eyehole canbe less noticeable and therefore less aesthetically objectionable. Thesize and spacing of the openings, as they contribute to percent openarea in the eyehole region, determine the transmittance of light to theglare sensor. Because the eyehole is part of the EC element, it darkenswhen the element is energized resulting in a change of light intensitymeasured by the glare sensor. It is preferable that the eyehole clear asquickly as the rest of the EC mirror element so that the measured lightintensity is accurately indicative of the glare observed by the driver.If the eyehole clears slower than the rest of the mirror element then itis possible that the EC mirror will not respond to changing glaresituations as intended.

There can be negative impacts on EC mirror element aesthetics andfunction caused by essentially non-conductive regions of the electrode.In the currently described electrochromic (EC) cell embodiments, the ECfluid comprises two primary coloring compounds, an anodic material,which is bleached in its normal state and becomes oxidized at the anodewhen the cell is energized, and a cathodic material, which is bleachedin its normal state and becomes reduced at the cathode when the cell isenergized. In one embodiment the anodic material is yellow/green in itscolored state and the cathodic material is violet in its colored state.Because these two EC materials are dissolved in the EC fluid, they arefree to diffuse through the cell. Therefore, when the operatingpotential is applied between the anode and cathode, the two EC activecompounds proximate to the proper electrode surface are converted totheir colored states. The colored state compounds diffuse away from theelectrode surfaces where they were created and are replaced by morebleached state compounds which are subsequently colored. When a moleculeof oxidized (colored) anodic material diffuses proximate to a moleculeof reduced (colored) cathodic material, there is some probability that acharge transfer reaction will occur, converting both molecules back intotheir bleached state. A second potential route to bleaching of a coloredstate molecule is diffusion to the opposite electrode from which it wascreated. A molecule of anodic material that has been oxidized at theanode has some probability of diffusing proximate to the cathodesurface. Once this occurs it is likely that the anodic material will bereduced back to its bleached state. Likewise, the same effect can applyto reduced cathodic material that diffuses to the anode. In this way,some time after the initial activation of the EC cell, steady stateequilibrium is reached between the creation of colored state compoundsand the bleaching of colored state compounds by intermolecular chargeexchange and diffusion to the opposite electrode. In the equilibriumstate, colored EC molecules have the highest probability of bleachingthrough intermolecular charge transfer with the opposite species in adepletion zone between the two electrodes where the concentration ofcolored species approaches zero. As described elsewhere, in a standardEC mirror cell design, surface 2 of the EC element comprises atransparent electrode which is commonly configured as the anode. Surface3 of the EC element comprises a conductive, reflective layer which iscommonly configured as the cathode. Considering the equilibriumdescribed above, if one considers the EC cell in cross-section, therewill be a somewhat higher concentration of colored anodic materialproximate the anode surface and a somewhat higher concentration ofcolored cathodic material proximate the cathode surface. Nearer thecenter of the cell (in cross-section), the concentrations of the coloredanodic and cathodic materials will be more similar until theconcentrations fall to near zero in the depletion zone. To an observerviewing the reflective element from a position normal to its firstsurface, the stratification of the colored species is not apparent sincethe layered colors are blended by the path the light takes to theobserver. Consequently, if there is a gap in one of the conductivelayers generating a non-conductive or significantly less conductiveregion (for example, an area 6610), a localized imbalance can be causedin the equilibrium. The side of the cell still having a functionalelectrode will generate colored material as described above. The side ofthe cell with the compromised electrode will not generate coloredmaterial or will do so at a significantly reduced rate. Therefore ifthere is a gap in the cathode of the above described embodiment,yellow/green material will be produced at the anode without commensurateviolet material being product at the opposing cathode location. Thisimbalance can lead to a net yellow/green appearance at the location ofthe compromised cathode. This color imbalance is here and elsewhere(U.S. Pat. Nos. 4,902,108 and 5,679,283 herein incorporated by referencein their entirety) referred to as segregation. This effect can lead toless than optimum aesthetics when the mirror element has been in thedark state for several minutes. The size or area of the compromised zoneof the electrode affects the degree of segregation due to its effect onthe diffusion length required to reach the other electrode. For example,in a non-compromised system with two parallel electrodes separated by140 microns, the shortest diffusion path length at any position in thesystem must be less than or equal to 140 microns. If a segment of anelectrode 500 microns wide is removed then the shortest diffusion pathlength can be as high as 287 microns in the compromised segment,describing the hypotenuse of the triangle running from the center of thecompromised segment to its edge then across to the other electrode ofthe EC cell. Increasing the shortest path length will increase theeffects of segregation. These effects are illustrated in FIG. 66F.

A common method of clearing the EC element involves removal of thedriving potential and electrical shorting of the anode to the cathode.At this point no new EC molecules are being converted to their coloredstates and diffusion takes over. The high concentration of oxidizedanodic species proximate the anode and reduced cathodic speciesproximate the cathode result in a chemical potential similar to abattery. Shorting the electrodes allows the species proximate to theelectrode surfaces to rapidly return to their bleached state. Diffusionacross the cell allows the remaining oxidized anodic molecules to bleachthrough charge transfer reactions with reduced cathodic molecules.Again, as described above, a non- or partially-conductive area of one ofthe electrodes means that the bleaching of one of the EC species cannotoccur at the compromised electrode surface resulting in diffusion beingthe only route to bleaching. If only one electrode, cathode or anode, iscompromised then one species may bleach more quickly than the otherresulting in a color imbalance and slower than normal clearing of thatspecies which is herein also considered a form of segregation. The sumeffect of one electrode having a non- or partially-conductive region isthat in the driven (darkened) state, one colored EC species increases inconcentration in the compromised zone, due to lack of depletion by theopposite EC species, until it dominates the color. This dominate colorpersists for some time after clearing of the EC element by the methoddescribed above due to diffusion being the only route to bleaching inthe compromised region. Depending on the size and shape of thecompromised zone, it is possible, due to the chemical potential presentduring clearing, to see a small amount of the violet color, for theabove described embodiment, proximate the perimeter of the compromisedzone during clearing. As described above, the colored EC speciespersisting in the eyehole zone longer than the clearing time for therest of the element may lead to less than optimum performance of theglare sensor.

As alluded to above, one route to minimizing the segregation effects isto compromise both the anode and cathode electrodes. So if the intent isto create openings or essentially non-conductive zones in the thirdsurface reflector layer to enhance transmission or create a conductancebreak, creating an essentially equivalent opening or essentiallynon-conductive zone in the opposing region of the second surfaceconductive layer will have roughly equivalent, offsetting effects,resulting in less segregation effects. This is due to the effect thatboth electrodes are compromised meaning that neither EC materialeffectively dominates in the compromised zone. This may significantlyreduce the color bias in the activated (dark) state as well as duringclearing. This may also reduce the lag in clearing time but will notnecessarily eliminate it.

Examples

EC-mirror elements were fabricated with nominal cell spacing ofapproximately 140 microns. The eyeholes in these devices were configuredby patterning the third surface metal reflector (cathode) with verticallines created by laser ablation in a fashion similar to that of FIG.66C. The perimeter of the ablated area approximated an oval with alength of about 5 mm and a width of about 7 mm. The width of theremaining metal traces and the width of the ablated openings in theeyehole area are shown in Table 6. Each of the samples was activated(darkened) for 10 minutes and then shorted (cleared). During thecoloring and clearing phases the eyehole region was observed bytransmittance spectroscopy to track the change in transmittance versustime. Examples A1-L1 represent openings in the surface 3 reflectivelayer without a corresponding “opening” in the surface 2 TCO. ExamplesA2-L2 represent openings in surface 2 plus corresponding essentiallyequivalent “openings” in the surface 2 TCO. FIG. 66G demonstrates thechange in transmittance at the eyehole during coloring and clearing forboth an element showing segregation effects and an element not showingsegregation. As can be seen from FIG. 66G, a non-compromised EC elementshows relatively monotonic change between the bright and dark stateswhile an EC element with a compromised electrode in the region of theeyehole shows a non-monotonic change both for coloring and clearing. Thesecondary, slow change identified as segregation in FIG. 66G is due tothe slow diffusion of colored state EC molecules into and out of thecompromised zone/s of the eyehole. A time measure, t₁, was assigned forthe time at which the primary rapid clearing step transitioned to theslow segregation clearing step. A second time measure, t₂, was assignedto the point at which the clearing reached essentially a steady statetransmittance. The difference between t₂ and t₁ was defined as theClearing Time Delay, Delta-t. The transmittance at time t₁ was definedas % T₁. Similarly the transmittance at time t₂ was defined as % T₂. Thevalue of % T₂ represents the transmittance of the eyehole in itsessentially fully clear state. The attenuation of light at time t₁relative to t₂ was defined as Delta-% I which represents the loss oflight intensity reaching the glare sensor at time t₁ relative to theintensity of light reaching the glare sensor in the fully clear state;in other words, the attenuation of the glare sensor response due tosegregation. Table 6 lists the properties of the example surface 3eyehole ablations including whether surface 2 was also ablated, thewidth of the metal traces, the width of the ablated spaces, the clearstate transmittance, the dark state transmittance and the variableslisted above. To minimize the effects of segregation on the performanceof the glare sensor it is preferable to minimize either the clearingtime delay, Delta-t, or the attenuation of the glare sensor, Delta-% I.Minimizing both measures will result in a preferable embodiment however;the minimization of either measure reduces the impact of the othermeasure.

TABLE 6 Surf2 Traces Ablations Darkened t1 t2 Delta- Label Ablation (um)(um) % Open % T % T sec sec Delta-t % T1 % T2 % T Delta-% I A1 N 54 5048 22.1 4.7 17 113 96 20.7 22.1 1.4 6.4 B1 N 123 50 29 14.1 2.7 13 68 5513.6 14.1 0.5 3.9 C1 N 210 50 19 9.2 1.8 16 42 26 9.1 9.2 0.1 0.8 D1 N81 75 48 23.6 7.5 20 130 110 21.2 23.6 2.4 10.2 E1 N 185 75 29 13.8 4.413 72 59 13.1 13.8 0.7 5.2 F1 N 315 75 19 10.1 3.4 16 50 34 9.8 10.1 0.32.8 J1 N 217 200 48 25.4 16.5 2 265 263 18.8 25.3 6.5 25.6 K1 N 490 20029 16.1 10.5 3 164 161 12.2 16.0 3.8 23.6 L1 N 853 200 19 9.4 6.1 3 9794 7.1 9.4 2.3 24.5 A2 Y 54 50 48 21.3 4.1 17 62 45 20.7 21.3 0.6 2.7 B2Y 123 50 29 13.6 2.4 20 42 22 13.5 13.6 0.1 0.9 C2 Y 210 50 19 9.0 1.723 28 5 8.9 9.0 0.1 0.6 D2 Y 81 75 48 23.8 6.2 20 70 50 23.3 23.8 0.52.3 E2 Y 185 75 29 13.6 4.2 20 42 22 13.6 13.6 0.0 0.3 F2 Y 315 75 199.6 3.1 18 22 4 9.6 9.6 0.0 0.4 G2 Y 69 251 78 40.6 29.8 9 229 220 36.640.5 3.9 9.6 H2 Y 158 481 75 38.9 25.0 4 324 320 26.6 38.9 12.3 31.6 J2Y 217 200 48 25.6 16.9 7 109 102 22.3 25.6 3.3 12.9 K2 Y 490 200 29 15.811.2 9 109 100 14.3 15.7 1.4 8.9 L2 Y 853 200 19 11.1 7.8 10 109 99 10.111.1 1.0 9.0

Another approach to quantifying the effects of segregation on the glaresensor response is to consider the lag between initiation of clearingthe EC element and the time at which the eyehole transmittance reaches apredetermined value. For this purpose it is convenient to consider anormalized Percent Full Scale (% FS) transmittance scale for theeyehole. The actual transmittance of the eyehole at any time t isnormalized and scaled such that the minimum transmittance of the eyeholein the fully darkened state becomes 0% FS and the maximum transmittanceof the eyehole in the fully cleared state becomes 100% FS. The behaviorof this measure for the clearing of selected examples is given in FIG.66H. This normalized scale is convenient because it more accuratelydescribes the effects of the segregation on the actual response range ofthe glare sensor. It is preferable that the eyehole reach a % FS valueof greater than 75% within 20 seconds of the initiation of clearing. Itis more preferable that the eyehole reach a % FS value of greater than80% within 20 seconds of the initiation of clearing. It is mostpreferable that the eyehole reach a % FS value of greater than 90%within 20 seconds of the initiation of clearing. The Percent Full Scaletransmittance data for the examples described above is given in Table 7.Tuning of the clearing speed and optical properties of the eyehole, asdescribed above, is controlled by the conductivity of the surface 2 andsurface 3 electrodes as well as the fraction open area in the surface 3electrode within the boundaries of the eyehole zone and the selection ofa metal trace (area 6620 of FIGS. 66A through 66 E) and open area (area6610 of FIGS. 66A through 66E) dimensions and geometry. It is thereforepreferable that the fraction of open area in the eyehole zone be between5 and 75 percent. It is more preferable that the fraction of open areain the eyehole zone be between 10 and 60 percent. It is most preferablethat the fraction of open area in the eyehole zone be between 15 and 50percent. It is preferable that the minimum dimension of the metal tracesbe between 1 and 1000 microns. It is more preferable that the minimumdimension of the metal traces be between 10 and 500 microns. It is mostpreferable that the minimum dimension of the metal traces be between 20and 250 microns. It is preferable that the maximum dimension of theopenings be between 1 and 1000 microns. It is more preferable that themaximum dimension of the openings be between 10 and 500 microns. It ismost preferable that the maximum dimension of the openings be between 20and 250 microns.

It is appreciated that the dimension of the remaining metal traces(areas 6620) in the eyehole zone may affect the performance of the glaresensor. If the traces are not small compared to the dimensions of theglare sensor, or its optics, then the shadowing of the sensor by themetal traces might result in the response of the glare sensor beingnon-uniform with respect to the angle of incidence of the light. Forthis reason the dimension and spacing of the metal traces may requireoptimization beyond the requirements of the segregation effectsdescribed above. Eyeholes comprising multiple smaller apertures may beconsidered less obtrusive and therefore more aesthetically pleasing thanlarger, single aperture eyeholes. The use of laser ablation to form theabove described apertures/ablations is one example of a potentialmanufacturing advantage over common methods used to generate conductive,single aperture eyeholes in a reflective conductive layer stack.

TABLE 7 Percent of Full Scale Transmittance. Time (sec) % Tmin % Tmax 01 2 3 4 5 6 7 8 9 10 15 20 25 30 A1 4.7 22.1 0 0.5 3.6 11.0 20.7 44.757.7 70.4 81.9 89.1 89.8 89.6 89.7 89.9 90.3 B1 2.7 14.1 0 0.8 5.3 12.421.3 42.6 54.0 65.4 76.1 85.8 93.0 95.1 95.4 96.1 96.7 C1 1.8 9.2 0 1.05.9 13.5 22.9 44.6 56.0 66.9 76.9 85.6 92.8 98.3 98.7 99.1 99.4 D1 7.523.6 0 1.2 7.4 16.7 27.7 52.1 64.3 75.5 82.9 85.8 85.9 85.3 85.3 85.485.7 E1 4.4 13.8 0 1.6 7.9 17.1 27.8 50.7 62.2 72.9 82.1 88.5 91.5 92.092.2 92.8 93.4 F1 3.4 10.1 0 1.1 7.3 17.3 29.0 53.6 65.2 75.9 84.9 91.094.3 96.2 96.9 97.6 98.4 J1 16.6 25.4 0 10.3 19.9 24.2 26.6 28.5 30.231.5 32.7 33.9 34.8 38.3 40.5 41.8 42.8 K1 10.5 16.1 0 12.6 23.4 28.632.3 34.8 37.2 39.3 41.2 43.0 44.7 51.1 55.7 59.2 61.9 L1 6.1 9.4 0 12.723.5 29.4 33.5 36.7 39.4 42.0 44.4 47.3 49.2 57.5 64.0 69.2 74.0 A2 4.121.3 0 0.2 4.0 11.1 20.2 43.7 53.5 64.7 75.1 84.1 91.3 96.6 97.1 97.798.1 B2 2.4 13.6 0 0.3 3.2 8.9 16.3 34.5 44.5 54.6 64.2 73.1 80.9 98.999.3 99.6 99.8 C2 1.7 9.0 0 0.5 3.7 9.8 17.7 36.9 47.1 56.9 66.3 74.781.9 99.6 99.9 99.9 100.0 D2 6.2 23.8 0 0.6 4.3 10.5 18.2 35.5 44.7 53.962.8 71.2 78.9 97.0 97.2 97.6 98.0 E2 4.2 13.6 0 1.4 6.8 14.9 24.4 44.554.3 63.4 71.8 79.4 85.7 99.1 99.3 99.5 99.6 F2 3.1 9.6 0 1.2 6.1 14.123.6 44.1 54.0 63.5 71.9 79.5 85.7 99.0 99.6 99.6 99.9 G2 30.0 40.6 05.8 15.4 26.3 37.5 45.6 51.9 57.0 60.8 62.2 62.7 65.0 67.2 69.0 70.9 H225.1 38.9 0 3.3 6.3 8.5 10.2 11.4 12.7 14.0 15.4 16.7 18.1 25.4 33.241.1 49.0 J2 16.9 25.6 0 13.0 25.8 37.0 45.9 51.9 56.4 59.6 62.3 64.566.7 75.1 80.7 84.9 88.0 K2 11.2 15.8 0 7.0 17.4 28.6 39.2 46.7 53.759.4 64.0 67.3 69.1 74.3 78.2 81.6 84.1 L2 7.8 11.1 0 5.7 15.4 26.4 37.645.6 52.6 58.4 63.0 66.1 68.6 74.0 77.9 81.1 84.1

Another approach to making the eyehole less noticeable is to locate atleast part of the light sensor behind the peripheral ring of spectralfilter material and, correspondingly, the eye-hole itself within thearea defined by the width of the peripheral ring. In such aconfiguration, the area where the reflector of the rear substrate of theEC-element is removed to form an eye-hole will be hidden from the viewerby the peripheral ring. This configuration, however, requires theperipheral ring to be sufficiently transmitting in the visible portionof the spectrum so that the light sensor could function properly. It isunderstood, that sufficient transmittance of a peripheral ring at awavelength of interest may be achieved by making the ring transflectiveas well as by ablating a portion of the ring material or depositing thering with the use of masking means. A transmission level of 3% to about50% in visible light is preferred in such an application, while in theUV portion of the spectrum the peripheral ring may still be configuredto remain opaque for protection of the seal and plug materials.

Similarly, mutual positioning of the light sensor and the associatedeye-hole with respect to the seal is also important. For example, if theseal material is essentially opaque in visible light it should notobstruct the light that the sensor detects. On the other hand, if theseal is sufficiently translucent, the sensor can be placed behind theseal area and the associated eye-hole area may overlap with the areaoccupied by the sealing material. The combination of the seal and thespectral filter material should have an overall visible lighttransmission of 3% to 50% for the same reasons as described above.

Yet another approach to configuring the eye-hole area is to simplyposition the light sensor behind a rear substrate with a non-patternedreflector that is sufficiently transmissive (between 3% and 50%) as is.This level of light transmittance can be obtained through the coatingdirectly or with a combination of light passing through the coating andthrough openings in the coating.

To eliminate the requirement for an eye-hole altogether, the light-glaresensor can be repositioned so that it is not screened from the viewer bythe EC-element. This type of construction is known in the art. Often theeyehole is placed in an area just above or below the mirror or anywherealong the periphery. The placement of the light sensor could be in anynumber of locations including in the mirror mount, in the headliner ofthe vehicle, near to or attached to the rear window, on the side mirror,or on the rear of the vehicle. The sensor could be a simple photo-opticsensor or a more complex camera or multiple camera system.

Some drivers of vehicles equipped with an automatically dimming mirrormay not be aware that they have the dimming mirror or, in some cases,they simply don't know when the device is working. To some automobilemanufacturers this reduces the value of the mirror. At times indicatorlights have been added to the autodimming mirror to indicate that thedevice is powered. Still, this indicator light does not demonstrate thefunction of the device. In self-dimming mirrors comprising a reflectiveperipheral ring, the darkening of the center of the mirror ishighlighted by the contrast to the reflective peripheral ring.Alternatively, configuring the mirror to have an area that does notdarken or that darkens or clears at a different rate as compared to theremaining portion of the mirror may also put the user on notice aboutthe operation of the auto-dimming mirror.

Reduction of Width of a Peripheral Ring.

Reduction of width of a peripheral ring may alleviate a problem ofresidual glare produced by the non-dimming peripheral area of the mirroreven when the EC-element of the EC-mirror is activated. If the ring isnarrowed, then the total amount of light reflected from it in thedirection of the user is reduced. Preferably, the width of theperipheral ring should be less than 4 mm, more preferably less than 3mm, and most preferably less than 2 mm.

When the peripheral ring as narrow as 2 mm, a portion of the wide sealmay become visible from the front of the rearview assembly. Thevisibility of the seal may be reduced or eliminated if the seal is madeof clear epoxy or a sealing material the color and index of refractionof which match those of the EC-medium sufficiently enough to remove theoptical interface between the seal and the EC-medium upon wetting. As aresult, the “exposed” to viewing portion of the seal will be effectivelyhidden from view in the “clear” mode of the EC-element. When theEC-element operates in the “dark” mode, the exposed portion of the sealjust as the peripheral ring itself will not color or dim, therebyimproving the appearance of the mirror element.

Alternatively, the reduction in width of the ring may require anappropriate reduction of the width of the seal, a dimensions of a plugin the seal, and even dimensions of buss contacts located behind andprotected by the ring from UV-exposure, especially in embodiments of anoutside rearview mirror. The widths of the seal, buss can be optimizedas follows:

1) Keeping the seal width to a minimum required to pass theenvironmental durability tests;

2) Judiciously selecting conductive buss materials possessing suchproperties (of adhesion, low gas permeation, and others) that would thebuss to either function as part of the seal or to simultaneouslyfunction as the buss and the seal. (Also, see, e.g., a discussion ofelement 852 in reference to FIGS. 22, 24);

3) Use electrical contacting modalities and methods that allow forincorporation of the electrical contacts within or under the seal(nanoparticle inks based on silver, nickel, copper; patterned metallictraces formed by metal deposition such as from metallo-organic systems,electroplating, or electroless plating; wire bonding of gold or aluminumwires or ribbons, as schematically shown in FIG. 67A);

4) Positioning the buss conductor primarily on the edge surface of themirror element;

5) Optimizing or eliminating at least one of transverse offsets betweenthe substrates of the EC-element thereby providing for extendingposition of the seal towards the outside edge of the peripheral ring.

The plug area can be optimized as follows:

1) Assuring that the size of the plug opening is no greater than thewidth of the seal, thereby enabling a controlled injection of a reducedamount of plug material;

2) Appropriately shaping a plug opening 6710 b, 6710 c, 6710 d to assurethat one dimension of the plug is greater than the width 6712 b, 6712 c,6712 d of the seal 6714 b, 6714 c, 6714 d as shown in top view of asubstrate 6720 of an EC-element in FIGS. 67(B-D);

3) Adhering a low-gas-permeability thin metal foil, plastic foil, orglass/ceramic, or adhesive along the edge surface of the EC-element orsoldering metal to the edge surface to cover the fill-port opening.(Also, see, e.g., discussion in reference to FIGS. 25, 27).

Rounded Ground Edge for Internal EC-Mirrors.

European regulations of automotive design require that a non-recessedhard edge of any element have a radius of at least 2.5 mm, as a safetymeasure. In response to such a requirement, a non-recessed perimeteredge of an inside automotive mirror may be covered with an appropriatebezel (and multiple embodiments of a combination of a bezel with amirror element have been discussed in this application, e.g., inreference to FIGS. 42-54 and 58, 59). To satisfy the Europeanregulations, a front lip of a bezel extending over the perimeter edge ofthe mirror element is designed with an outer radius of at least 2.5 mm.As further discussed in this application, a mirrors that has an about5-mm-wide peripheral ring covering the seal from exposure to light (suchas chrome ring mirrors, for example) may have no bezel extending outonto the first surface of the mirror. For aesthetic reasons it is oftendesirable to either not have a perimeter bezel or have a bezel with alip that surrounds the perimeter edge of the mirror and is substantiallyleveled with the front mirror element. If the bezel must meet theEuropean edge design requirements and it is flush with the front surfaceof the mirror, the bezel must be configured to have an at least 2.5 mmradius curvature, which means that the overall transverse dimensions ofthe rearview assembly as viewed from the front of it are at least 5 mmlarger than the transverse dimensions of the mirror element. Neitherthis rounded bezel nor a peripheral ring contributes to the auto-dimmingreflective portion of the mirror and, together, the rounded bezel andthe ring add an at least 7.5 mm wide non-dimmable ring around the mirrorelement. Moreover, the addition of a wide bezel also detracts from thesleek appearance of the mirror assembly.

One bezel-less embodiment 6800 meeting the European edge requirement andproviding for a durable edge of the mirror is schematically illustratedin FIG. 68. As shown, a mirror element 6801 includes a front substrate6802 having a thickness of t≧2.5 mm and a rear substrate 6804 that arepositioned in spaced-apart and parallel relationship with respect to oneanother, a seal 6806 disposed around the perimeter of the element 6801so as to sealably bond the front and rear substrates 6802, 6804 and toform a cavity 6808 therebetween. A peripheral portion of the frontsubstrate 6802 is configured by, e.g., grinding to form a curvature,around the front edge of the front surface 6802 a, with a radius Rad=2.5mm or bigger. The rear substrate 6804 is smaller than the frontsubstrate 6802 and is transversely offset with respect to the frontsubstrate 6802 along most of the perimeter of the mirror element 6801.As shown, a peripheral ring 6810 is disposed circumferentially in aperipheral area of the second surface of the element 6801 on top of atransparent TCO-electrode 6812 in such a fashion as to block visibleand/or UV light incident onto the first surface 6802 a from illuminatingthe seal 6804. (It is appreciated, however, that in a related embodimentthe TCO-electrode can be deposited on top of the peripheral ring,instead.) A generally multi-layer thin-film stack 6814, disposed on athird surface 6816, includes at least one electrically conductive layerthat is electrically extended over an edge surface 6818 of the rearsubstrate 6804 to the back of the element 6801 (as shown, a fourthsurface 6820) through a conductive section 6822. In a specificembodiment, a multi-layer thin-film stack may be a reflective electrodeat least one electrically conductive layer of which is configured to bein electrically communication with the back of the mirror element.Another buss connection, 6824, provides for an electrical communicationbetween the transparent electrode 6812 and the fourth surface 6820. Thisrecessed back substrate design would provide for uninterruptedelectrical contact from the back of the embodiment to the front and/orrear electrode(s). The mirror-holding system could be designed such thatthe mirror element 6801 is supported by a carrier 6830 having ajudiciously formatted perimeter lip or wall 6830A that is flush with anedge of the front glass substrate 6802 and that covers the perimeteredge 6818 of the second glass substrate 6804 hiding it from view. Aground or frosted appearance on all visible glass edges is aestheticallypreferred.

It would be appreciated that the use of a front substrate 6804 that isat least 2.5 mm thick will increase the overall weight of the mirrorelement 6801. Using glass plate that is 2.2 mm or less in thickness ispreferred. Using glass plate that is 1.6 mm thick or thinner is mostpreferred. In such preferred cases of thinner substrates, the edgesurface of the overall mirror element could be rounded to a radius of atleast 2.5 mm to meet European specifications. It will be understood thatthis approach results in making either one of the electrodes or a clip,providing for electrical communications between the electrodes and theback of the mirror element, visible from the front of the mirrorelement.

One solution to this problem, in reference to FIG. 69A, is to configurethe second substrate 6904 of the mirror element 6906 with a recess orindentation 6908 in which an electrical buss (clip of electricallyconductive section) is fit over the edge surface of the rear substrate6904. FIG. 69B demonstrates a front view of a stack of the firstsubstrate 6910 and the second substrate 6904. FIG. 69C schematicallyshows the rounded profile added to the edge surface of an assembledmirror element in the area of the recess 6908. As shown, post assembly,the recessed area 6908 of the substrate 6904 can be filled with amaterial 6912 that simulates the look of ground glass, such as aUV-curable acrylic resin filled with glass flakes. The assembled mirrorelement is then shaped to a rounded profile, Rad, as described above,around a perimeter of the mirror element.

Rounded Carrier/Bezel Edge.

Alternative solutions addressing the European requirements of safety maybe based on configuring a frame of the mirror without a lip extendingonto the first surface of the mirror and with a rounded edge. Further tothe discussion presented in reference to FIG. 39, aesthetic requirementscurrently dictating a color match between the rearview assembly and avehicular dash board would be met if the mirror frame had a metallicappearance. Several embodiments implementing such solutions areschematically shown in FIGS. 70-72.

As shown in a partial side view and a front view in FIGS. 70(A, B), anembodiment 7000 of a multi-piece frame construction of the mirrorelement 7010 of the invention includes a carrier 7012 supporting themirror element 7010 and attached to a housing 7014 and a bezel 7016stamped of metal and attached to the carrier 7012 with adhesive. In arelated embodiment, the metallic bezel 7016 may be snapped orinsert-molded into the carrier 7012. As shown, the embodiment of thebezel 7016 has a front lip 7018 extending over the first surface 7020 ofthe mirror element 7010. In a specific embodiment, the bezel 7016 may bemolded out of plastic and plated with metal. It is appreciated that,generally, no peripheral ring is required within the mirror element 7010because a seal 7026 of the mirror element is protected from lightexposure by the lip 7018.

A partial side view and two different front views of an alternativebezel-less embodiment 7100, 7100′ of a mirror frame are presented inFIGS. 71(A-C). As shown, a decorative inlay 7102 is inserted into afront surface 7104 of a carrier 7106 having a rounded bound, Rad≧2.5 mm,that levels the front surface 7104 with the first surface 7108 of themirror element 7110. In this configuration, the frame 7100 does notobstruct the front surface of the mirror element. The decorative inlay7102 may be stamped of metal or extruded from plastic and plated withmetal, and attached to the carrier 7106 with adhesive, by snapping, orinsert molding. It is appreciated that, to be used with this embodimentof the frame, the mirror element should incorporate a peripheral ring(not shown) to protect a seal 7126 from exposure to light. The frontviews of FIGS. 71B and 71C illustrate, respectively, that the inlay 7102may or may not be present around the entire perimeter of the mirrorelement 7110.

FIGS. 72(A-C) show, in side views and in front view, two morealternative bezel-less embodiments 7200, 7200′ satisfying the Europeansafety and aesthetic requirements. As shown in a multi-piece embodiment7200, a carrier plate 7202 has a front surface 7204 rounded with aradius Rad≧2.5 mm and leveled with the front surface 7108 of the mirrorelement 7110. A decorative insert 7212 of the embodiment 7200 is similarto the insert 7102 if the embodiment 7100, but extends further towardsthe housing 7014 of the assembly thereby providing for an uninterruptedmetallic appearance of the frame in the front view, FIG. 72C. A specificsingle-piece embodiment 7200′ of FIG. 72B provides for metal-plating,painting, pad-printing or hydrographic decorating 7220 of the frontsurface of the carrier 7202 to assure the metallic appearance in a frontview of FIG. 72C.

User Interface.

As was discussed in reference to FIGS. 4 and 61-64, various operatorinterface elements including buttons have been conventionally positionedin a housing or a mounting element that wraps around the edge surface ofthe mirror system (such as a bezel with a lip extending onto the firstsurface). To accommodate the interface modalities, the mounting elementhas to possess sufficient width. For example, a chin of the bezelcontaining buttons and switches of the user interface typically has tobe wider than the remaining portion of the bezel including a lip thatextends onto the first surface of the mirror system. Some practicalsystems, e.g., employ a bezel with a chin portion that may be as wide as20 mm. Incorporating of the user-interface components into such widemounting element causes several problems. Firstly, the presence of amounting element with mirror having a surface of a given size increasesthe overall width of the rearview assembly by the width of the mountingelement, thereby blocking the front view of the road to such a degreethat a driver may experience discomfort. Secondly, a risk of misplacingor tilting the rearview assembly when pressing a mechanicaluser-interface button positioned near the edge of the assembly, in thechin of the mounting element, is increased, which causes the driver torestore the rear field of view by manually re-adjusting the assembly.Understandably, this re-adjustment may be a source of distraction to adriver. In addition, disposing movable parts such as buttons within themounting element without additional precautions is recognized toincrease the level of noise such as rattling or squeaking, which mayreduce the driver's comfort on the road.

The first of the abovementioned problems, related to increasing theeffective area of the mirror system perceivable by the user withoutnecessarily increasing the overall size of the rearview assembly, hasbeen already discussed in this application. Solutions proposed hereininclude the use of a lip-less bezel (or a bezel with reduced width, orno bezel at all) in combination with the use of a peripheral ring thevisual appearance of which satisfies the auto-manufacturer'srequirements (e.g., substantially matches the appearance of the centralportion of the mirror, both in terms of color and irradiance ofreflected light; or has a different aesthetics and/or provides amulti-band appearance). Such “reduced bezel approach”, however, begs aquestion of how to re-configure the mirror system in order to notsacrifice any of the interface and/or indicator modalities that havebeen conventionally housed within the wide portion of the mountingelement of the mirror.

Embodiments of a user interface of a rearview assembly addressing thisquestion and discussed below can be enabled in combination with anyembodiment of the rearview assembly including that employing a prismaticelement; or that employing a peripheral ring; and with any configurationof the mounting element (bezel, carrier, housing) discussed elsewhere inthis application, in particular with those discussed in reference toFIGS. 42-54 and 58, 59, 68-72. In particular, references madespecifically to EC-elements are made for convenience and illustrationpurposes only: the scope of invention also includes rearview assembliesemploying prismatic elements even if no corresponding drawings areprovided.

According to embodiments discussed below, elements of user interfaceinclude various functional elements such as switches, sensors, and otheractuators of the rearview assembly that may be operated with nomechanical activation. Such switching elements or sensors are activatedby a user input that may include placing a driver's finger in closeproximity to the switching element or sensor. Alternatively, thefunctional element is activated when the user slightly touches on acomponent of the functional element such as, for example, a conductivepad. In response to such user input, the switching element activates,triggers, or switches one of auxiliary devices that are located insidethe assembly and that may exchange visual or audio information with theuser. For example, an auxiliary device may be a display that forms animage to be observed by the user through the mirror element of theassembly. In another example, an auxiliary device may include a voiceactivated system that will await for an audio input from the user toperform a required operation. Although sensing solutions have beenimplemented in different arts, the inventors are not aware of any suchapplication in automotive rearview assemblies. Relevant art does notappear to consider the use of non-mechanical sensing components invehicular rearview assembly. Indicia of non-obviousness of use ofcurrently existing non-mechanical sensing solutions in rearviewassemblies include high cost of the sensors, limited sensitivity rangesthat are below the level required to recognize the presence of adriver's hand wearing a glove, and susceptibility to false triggering.

In addition or alternatively, proposed implementations of the userinterface facilitate reduction of size or, in specific embodiments, evenelimination of a rim-like portion of the mounting element conventionallyextending around the edge surface of the mirror system of the invention.Embodiments of the user interface of the invention include an opticalswitch, a capacitive on-glass switch, a capacitive through-glass switch,a capacitive in-glass switch, a capacitive glass-edge switch, acapacitive through-bezel switch, a capacitive conductive bezel switch, aconventional capacitive or a resistive touch-screen-based switch, or awaveguide-based sensor. According to the embodiments discussed below,either positioning the user's finger in proximity of a sensor or aswitch of an embodiment or a gentle touch on a sensing pad locatedadjacent to the surface of the mirror system induces the rearviewassembly to activate a required function such as, e.g., illumination ofa portion of a display, or dimming or clearing of an electro-opticelement of the assembly. Because the operation of the user-interfaceembodiments of the invention may include touching an area of the firstsurface of the mirror element, this surface may be appropriately treatedwith a finger-print dissipating coating such as the Opcuity filmprovided by Uni-Pixel Inc. (Clear View™). If an input area is configuredoutside of the primary reflective area of the mirror, a matte finish maybe used to resist fingerprints.

In describing embodiments of a non-mechanically activated user interfaceof the invention, references are made to a legend, or indicia,corresponding to a particular sensor, or a switch, or an actuator. Inthis context, a legend/indicia refers to a physical marking or anindication, disposed on one of the surfaces of an embodiment in such afashion as to be perceived to correspond to a given sensor, thatprovides identification of the given sensor and its function to the useractivating this sensor. Generally, a legend or its equivalents may beconfigured in an opaque, transfiective or translucent layer deposited onor inserted into a surface (by, e.g., masking out a portion of the layerduring deposition or by pre-molding an inlay that is further implantedinto a component) to form a required graphical or textual identifierthat is appropriately made visible to the user. For example, as will bediscussed below, a legend may be configured in an overlay patch disposedon a first surface of the mirror system or on a mounting element; in athin-film stack of either the second or third surfaces of the mirrorsystem; or in a surface of the mounting element that is visuallyaccessible by the user. According to present embodiments, the mostcommon way of causing a legend to be visible is to highlight the legendwith a source of light located behind the legend with respect to theuser. It is understood that even when only a particular implementationof a legend is referred to in a description of an embodiment, otherappropriate implementations are considered to be within the scope of theinvention and are implied.

Optical-switch-based embodiments of the user interface may include atleast one of a line-of-sight sensor (interrupter) and a reflectivesensor. FIGS. 73(A-C), for example, illustrate an optical interrupterthat is employed in an interface of an embodiment 7300 of the rearviewassembly and that includes an IR photodiode and an LED pair (althoughmultiple pairs may be present, corresponding to multiple interrupters).A shown, an emitter 7302 and a receiver (detector) 7304 form aline-of-sight sensor and are respectively disposed in opposing (asshown, top and bottom) portions of a mounting element 7310 thatsurrounds an edge surface 7312 a mirror element 7314 and slightlyprotrudes over a first surface 7314 a toward an outside portion of therearview assembly. In one embodiment, the mounting element 7310 may beeither a bezel or a carrier of the mirror system supporting the systemin the assembly. When the user interrupts an optical connectionestablished between the emitter and detector and shown with an arrow(optical path) 7320 in FIG. 73B by placing a finger across this opticalpath, the detector is caused to lose the reception of optical signal,which in turn triggers the sensor's response to this user input. Toincrease a signal-to-noise ratio of the embodiment and to reduce orreject signal interference from ambient lighting, the operation of theemitter 7302 may be modulated at a high frequency allowing the detector7304 to be AC-coupled.

A rearview assembly function to be initiated by the user input throughactivation of the line-of-sight sensor 7302, 7304 may be indicated witha use of a graphic- or text-based legend 7322 associated with a displayof the rearview assembly and located, e.g., within the boundaries of themounting element 7310 on the first surface 7314 a of the mirror element7314. (It is appreciated that, in a related embodiment, when therearview assembly contains transflective coatings such legend may beappropriately formatted in a coating disposed on either a second or athird surface, e.g., by judiciously masking a legend portion of thecoating during the deposition process). In a specific embodiment, thelegend 7322 may be made visible by backlighting when required.Backlighting of the legend may be provided by a simple LED, optionallywith appropriate masking, or with the use of an illuminated LCD or anOLED-display from behind the element 7314. Alternatively, the legend maybe incorporated in the assembly as a permanently visible graphic.

In one embodiment, the optical communication 7320 between the emitterand detector of a line-of-sight sensor of the embodiment 7300 isestablished through optical windows (not shown) covering the emitter anddetector. Such windows may be fabricated from IR-grade transparent ortranslucent plastics that in the visible portion of the spectrum areperceived as being almost black and, therefore, may be color-matchedwith the dark mounting element 7310 to disguise the sensor areas. In aspecific embodiment, the emitter/detector pair(s) may also be mounted inthe mounting element in such a way as to provide a small gap near theglass that is covered in front by IR-light-transmitting plastic.Alternatively, as shown in FIG. 73C, the detector 7304′ may be disposedin the back of the mirror system 7314 and light pipes 7326 may beconfigured to deliver IR-light 7320 to the detector 7304′. Similarly, ina related embodiment (not shown), the emitter 7302 may be disposed inthe back of the mirror system, delivering light towards the front of themirror system via another light pipe. Optionally, the hard edge of themounting element 7310 may be rounded, preferably with a radius Rad of atleast 2.5 mm, as illustrated in FIG. 73C and discussed in reference toFIGS. 70-72.

Although only a single emitter/detector pair is shown in FIG. 73A,generally a plurality of such pairs may be employed. To this end, FIG.74 schematically illustrates a specific embodiment including 3line-of-sight sensors (3 pairs of emitters/detectors (E1, D1), (E2, D2),and (E3, D3)). In such a multi-sensor case, a process of identificationof which line-of-sight among those connecting the emitters and thedetector is interrupted by the user may be facilitated by operating theemitters E1, E2, and E3 in an alternating fashion. In one embodiment,the emitters are turned “on” one at a time. Once a given emitter isswitched “on”, all receivers are tested for signal. Based on which lightpath is blocked by the user's finger, six operational modes can beidentified, as shown in Table 8 corresponding to the embodiment of FIG.74. These modes allow the electronic circuitry of the rearview assemblysystem to decide which light-path connecting which pair of theemitter/detector has been blocked by a user (based on, e.g., a look-uptable) and, consequently, to activate a corresponding function of therearview assembly:

TABLE 8 Emitter/Detector (0 = blocked, 1 = signal) E1/D1 E1/D2 E1/D3E2/D1 E2/D2 E2/D3 E3/D1 E3/D2 E3/D3 Zone 0 0 0 1 1 1 1 1 1 1 1 1 1 0 0 01 1 1 2 1 1 1 1 1 1 0 0 0 3 0 1 1 0 1 1 0 1 1 4 1 0 1 1 0 1 1 0 1 5 1 10 1 1 0 1 1 0 6An indicia or legend employed with this embodiment may be dynamic andconfigured to be perceived as located on a surface of the mirrorelement. For example, a legend may be formatted as an options menu thatis not highlighted from behind (not visible to the user) during normaloperation of the rearview assembly. However, activation of a userinterface by any user input triggers highlighting of the indicia. Thehighlighting of the indicia may also be enabled automatically at vehicleignition on. In various embodiments, the indicia is configured with abitmapped display, or with a segmented displays or with masked backlitregions. Additionally, information contained in the legend may also beexpressed through brightness of a legend-highlight or color (e.g., greenor bright to indicate that a function is enabled and red or dim toindicate that a function is disabled).

An embodiment of user interface of the invention employing opticalreflective sensors operating in, e.g., IR-light is schematically shownin FIG. 75. As shown, the emitters and detectors of the “reflective”embodiments are disposed on the same side of the mirror element,side-by-side. A group 7510 of emitters disposed in the mounting element7310 of the assembly, while a group of detectors is positioned at a backportion of the mirror element 7314 so as to be aligned with eye-holeopenings 7512. The sensor system of either embodiment is then triggeredwhen light emitted by an emitter reflects from the user's finger and isdetected by a detector of the group through an eye-hole opening. The useof a visible-light reflective sensor instead of the IR-light-basedsensor may provide an additional advantage of illuminating an area ofinterest for the user. In such an embodiment, operation of the emittermay also be modulated at a high frequency to increase a signal-to-noiseratio and reject interference due to ambient light. To minimize directcoupling of light from the emitter to the detector in the absence of thetriggering action by the user, an appropriate optical blocking barrier(not shown) may be disposed between the emitter and the detector. Alegend (not shown) can be combined with an optical opening (e.g.,overlaid upon it or be formed in one of the thin-film coatings that areinternal to the EC-cell, as discussed above) to convey the informationabout the purpose of a switch to the user.

FIG. 76 illustrates an alternative embodiment 7600 operating in areflective mode that, in addition to detecting the user input, iscapable of providing positional information in a touch-type sensorapplication with the use in a vehicular rearview assembly. As shown, apair of IR emitters E1, E2 is used in conjunction with a single receiverD disposed between the emitters. It is understood that lines-of-sightcorresponding to the optical devices E1, E2, and D are directed alongthe first surface 7314 a of the mirror element 7314. In operation, theemitters are alternately enabled, and the user establishes opticalconnections between the emitters and a detector by placing a finger(“reflector”) in a proximity of the detectors thereby reflectingportions of light, emanating from each of the emitters, towards thedetector. Resulting optical signals are measured by the photodiode D.The ratio of the signals associated with the emitters provides thesystem with positional information about a location of the “reflector”(i.e., left or right with respect to the detector D). The sum of the twosignals provides vertical position information. As a result, a rearviewassembly employing the embodiment 7600 is capable of sensing andspatially resolving multiple positions, across the surface of the mirrorelement, at which the user communicates with the user interface of theassembly. At these positions, virtual “touching pads” of a touch-screensensor or switch may be deployed. A legend for such a sensor can beprovided in a fashion similar to that described in reference to FIG. 74.In a specific embodiment, a touch-sensor system such as that provided bythe QuickSense product line of the Silicon Labs (Austin, Tex.;www.siliconlabs.com) can be used. Because the described system canresolve both X and Y positional information, multiple user-interfaceoptions are enabled. In one embodiment, virtual touch pads areconfigured with the use of a programmable LCD or OLED-display locatedbehind the mirror element. Pressing these virtual touch pads causes theactivation of corresponding functions. The X/Y position information canalso be used to control a cursor, similar to that of a personalcomputer. Tapping or pressing various regions of the display would actlike a mouse click on a computer. Dragging a finger across the displaysurface can also act like a ‘drag’ function, and is useful for actionssuch as scrolling a map in a navigation display, or to switch betweenmenu pages.

Capacitive sensors that detect finger pressure applied to a particularsensing pad are generally known. Various capacitive sensors areavailable from the Silicon Labs, TouchSensor (Wheaton, Ill.;www.touchsensor.com), AlSentis (Holland, Mich.; www.alsentis.com), andMicrochip (Chandler, Ariz.; www.microchip.com). Some of capacitivesensors operate on the basis of a field effect and are structured toinclude a conductive sensor area surrounded with a conducting ring.Capacitive coupling between these two conductors is increased when theuser places his finger in close proximity.

According to an alternative embodiment of the present invention, acapacitive sensor of the user interface of the rearview assembly isconfigured in an “on-glass” fashion and has a sensing area, on the firstsurface of the mirror element, that is in electrical communication withan electronic circuit board disposed at the back of the assembly. (Ifmultiple sensing areas are present, these areas are electricallyisolated from each other). As shown in a cross-sectional view of inFIGS. 77(A, B), a layer of electrically-conductive material 7702 forminga front sensing area (or front sensing pad) is disposed on the firstsurface 7314 a of the mirror element 7314. The front conductive pad 7702is electrically extended through a connector 7708 to the back of themirror element. In one embodiment, FIG. 77A, such electrical extensionassures a direct electrical connection with control electronics on a PCB7706, in which case the connector 7708 may be a pin. An alternativeembodiment shown in FIG. 77B employs an electrically-conductive bridge7710, fabricated of metal or carbon-loaded ink, between the frontconductive pad 7702 and a back conductive pad 7712 positioned at theback of the mirror element 7314 (on the fourth surface of the mirrorelement or on a different element in the back of the mirror). The backcontact area 7712 can then be further connected to the PCB 7706 by aspring contact or other well-known contacting means 7716. In a specificembodiment, a conductive elastomer may be used instead of the springcontact. It has been unexpectedly discovered that configuring the backconductive pad 7712 to have a smaller lateral extent than that of thefront conductive pad 7702 facilitates the increase of signal-to-noiseratio of operating sensor by reducing offset capacitance to the groundof the system. Therefore, in a preferred embodiment the back conductivepad has a smaller lateral extent as compared to the front conductivepad.

An alternative version of the front-to-back electrical connection of acapacitive sensor may use a conductive adhesive tape or a flex circuitleading from the first surface to the controlling PCB. The top surfaceof the flex circuit could also include the indicia, finger printresistant coatings, a metallic or reflective cosmetic layer, and aninsulating layer (such as a non-conductive layer 7704) reducing a staticspark during the operation of the embodiment and increasing theelectrostatic discharge (ESD) tolerance of the system.

Suitable top conductive areas or pads may be produced by metalliccoatings manufactured with electroplating, vacuum deposition, oradhesive-based conductors, metallic or carbon based conductive inks. Theelectrically-conductive coatings may employ copper nickel, stainlesssteel, or transparent coatings such as ITO. Non-transparent coatings canbe patterned in a way such as to allow light form a backlight to passthrough and illuminate the top cosmetic overlay 7704 or a legend (notshown) that may include information indicia for the convenience of theuser. In the alternative, the conductive pad 7702 itself may bepatterned and used as a legend for the corresponding switch. If desired,conductors such as carbon ink can be used as an underlayment color for alegend on the first surface of the mirror element. It is appreciatedthat the hard edge of the mounting element (if present) may be rounded,preferably with a radius Rad of at least 2.5 mm, as discussed inreference to FIGS. 70-72. Alternatively, if embodiments of FIGS. 77(A,B)are configured to be bezel-less, the front glass component may beappropriately rounded in a fashion similar to that discussed inreference to FIG. 68.

Embodiments of capacitive and field effect-based sensors for use withembodiments of rearview assembly of the invention can also be configuredin a “through-the-glass” fashion. This requires that the sensor area benot shielded by a conductive layer, or at least that any presentconductive shielding layer is small and electrically isolated from otherparts of the circuit. Several alternative configurations of theinvention employing a through-the-glass capacitive or field-effect basedsensor 7802 are shown in FIGS. 78(A-C). FIG. 78A demonstrates anembodiment in which the two substrates of an EC-element 7804 are nottransversely offset with respect to one another, while FIG. 78B shows anembodiment with a transverse offset between the substrates of theEC-element. Various mounting elements and housing, electricalconnectors, auxiliary thin-film coatings are not shown in FIG. 78 forsimplicity of illustration.

As shown in FIGS. 78A and 78B, both a seal 7806 andelectrically-conductive coatings 7808 of the EC-element 7804 are placedfar enough inboard of the EC-element with respect to a seal 7806 to keepthe EC-medium from shielding the front and back sensor pads 7702, 7802and/or providing electrical interference with its operation.(Optionally, the transfiective conductive coatings of the EC-element mayhave external portions 7808′ as shown in a dashed line in FIG. 78A. APCB or flex circuit is located at the back side of the element. Thefront sensing pad 7702 may have an insulating overlay and a legend (notshown) carried thereon, and the circuitry may optionally contain LEDs toilluminate a touch pad area (corresponding to the overlay 7704) employedby the user to activate the sensor.

In comparison with FIGS. 78A and 78B, where the seal 7806 is configuredto be narrow and transversely offset with respect to the sensor pads,the embodiment of FIG. 78C illustrates a situation where the seal 7806′is configured to be wide and placed in the area of the sensor (betweenthe front and back conductive pads 7702, 7802). This embodiment mayrequire a use of wide peripheral ring configured to extend over the seal7806′. Here, the seal is made of material that is transparent or atleast translucent at the wavelengths of light used to backlight theindicia/legend on the front of the mirror element through the mirrorelement. In addition, the seal material can also be adapted to opticallydiffuse light to provide for optically diffusive appearance of the firstsurface indicia. “Through-the-glass” sensing embodiments of userinterface for use with rearview assembly additionally improve the ESDprotection of the sensor electronics. It is appreciated that the hardedge of the mounting element (not shown) may be rounded, preferably witha radius Rad of at least 2.5 mm, as discussed in reference to FIGS.70-72. Alternatively, if embodiments of FIGS. 78(A,B) are configured tobe bezel-less, the front glass component may be appropriately rounded ina fashion similar to that discussed in reference to FIG. 68.

In embodiments of the user interface of the present invention thatutilize capacitive “in-glass” based sensors, the electrically conductivelayers and connectors positioned internally with respect to theEC-element are configured to serve as sensor areas. In one embodiment,schematically shown in FIGS. 79(A, B), a transparent electrode 7912 ofthe EC-element 7910 (located, as discussed, on the second surface 7910 bof the element) is configured to have electrically independent portions7912 a, 7912 b, where the portion 7912 a forms a sensing area. Thereflective electrode 7914 of the third surface of the EC-element ispreferably isolated into portions 7914 a and 7914 b, where the outerportion 7914 a corresponds to the sensor area 7819 and is optional (asindicated by a dashed line). When the two portions 7914 a, 7914 b areelectrically connected and form a single electrically-conductive coating(not shown), it is preferred to keep the reflective electrode at or neara ground potential. As shown, the seal 7916 is appropriately positionedin-board with respect to the sensor area 7918 to prevent electricalinteraction between the sensor area and the electrochromic gel (notshown). In a related embodiment (not shown), where the sealing materialmay be extended into the sensing area 7918, the seal 7916 is configuredto be translucent (either clear or optically diffusing) to allow forbacklighting of a legend (not shown) corresponding to the sensor. (As inany of the user interface embodiments discussed in this application, alegend may be located on the first surface of the embodiment or,alternatively, in a non-transparent inner layer of the EC-element, ormay be backlit by masking or programmable display.) FIG. 79B illustratesa front view of the embodiment of FIG. 79A, where the reflectiveelectrode 7914 includes two portions—the outer portion 7914 acorresponding to the sensor area 7918 and the inner portion 7914 bcorresponding to the central area of the mirror system of the rearviewassembly. The portions 7914 a and 7914 b are then electrically isolatedfrom one another with an isolation trench or area 620 c created in thereflective electrode as discussed elsewhere herein. FIG. 79Bschematically illustrates, in top view, one possible way to dispose theseal 7916 around the electrical connector 7920 submerged in epoxy 7922.In one embodiment, the epoxy may be non-conductive. Although neither amounting element nor auxiliary electrical connectors have been shown inFIGS. 79(A,B), it is appreciated that, in a specific embodiment, themounting element including a bezel may be present. In this case, thehard edge of such mounting element is preferably rounded with a radiusRad of at least 2.5 mm, as illustrated in FIG. 73C and discussed inreference to FIGS. 70-72. Alternatively, if embodiments of FIGS. 78(A,B)are configured to be bezel-less, the edge of glass component may beappropriately rounded in a fashion similar to that discussed inreference to FIG. 68.

In a capacitive glass-edge embodiment of the user interface (not shown),spatially isolated electrically-conductive connectors such as metallictabs or conductive coatings are added to the edge of the glass or on theinner surface of the mounting element. In a specific embodiment, such aconnector may extend inboard with respect to the edge surface of theEC-element. The conductive epoxy currently being used may be segmented,and separate segments are then electrically contacted to the PCB.

A capacitive through-bezel type of interface sensor embodiment,schematically shown in FIGS. 79 (C, D), a flex circuit or an electricalconductor 7930 is placed behind and underneath the mounting element 7932having a front lip 7934 extending onto the first surface 7314 a of themirror EC-element 7314 and, preferably, having a rounded profile with aradius of at least 2.5 mm. The embodiment of the sensor or switch isactivated when the user touches a front pad 7940 configured on a frontsurface of the mounting element 7932 to carry a legend or indicia. Inanother embodiment, where several front pads 7940 are present that aremade electrically conductive, these pads separated by correspondingnon-conductive areas 7942. (If front pads are made electricallyconductive by appropriate deposition of an electrically conductive filmor by use of an electrically-conductive insert as described elsewhereherein, the separating areas 7942 are made non-conductive.) The flexcircuit 7930 may have several extensions behind the lip 7934, with eachextension positioned to correspond to a different front pad.Alternatively, several individual flex circuits could be used for eachof the sensors corresponding to each of the front pads 7940. Flexcircuit may optionally contain the sensing electronics and LEDs. Aleaf-spring contact 7946 to the main board 7948 could be used instead ofa wire to establish a required electrical connection. It is appreciatedthat a sensor legend (not shown) may be disposed on a surface of thefront lip 7914 visible to the viewer 115, and the mounting element maybe made of translucent material, in which case the legend ishighlighted, e.g., by light channeled by the mounting element from alight source (such as LED, not shown) at the back of the system. In arelated embodiment, the element 7930 may be a simple contactingelectrically-conductive layer such as a foil, a mesh, or a thin-filmlayer establishing the electrical communication with the main board atthe back of the system. A related alternative embodiment isschematically illustrated in FIG. 79E, where an electrical conductor7950 is disposed on the inner surface of a lip-less mounting element7932′ substantially surrounding the edge surface 7312 and partiallyextends to a front, outer surface 7952 of the mounting element A secondelectrical conductor 7954 such as a leaf-spring is adapted to provideelectrical connection between a conductive pad (not shown) of a mainboard 7948 and the front surface 7952 of the mounting element 7932′. Inthis embodiment, a front pad 7940′ carrying a legend may be configuredon either both the front surface 7952 of the mounting element and aperipheral portion of the first surface 7314 a of the mirror element7314 as shown, or, alternatively, only on the front surface 7952 of themounting element.

Another alternative embodiment of a component of a user-interface sensor(such as a capacitive sensor or a field sensor) of the inventionoperating as a switch for an auxiliary device located inside theassembly is shown in cross-sectional and front views in FIGS. 79F and79G, where a plastic cap 7955, providing a tray-like covering for aperipheral portion of the mirror element 7314, is used to configure thecomponent in issue. An inner surface of the removable cap 7955, which isappropriately sized to assure a close fitting around the edge surface7312 of the mirror element 7314 and is appropriately shaped tosufficiently extend onto and both the first surface 7314 a and over theback 7955 a of the mirror element, is overlayed with anelectrically-conductive covering 7955 b forming a thin-film layer, afoil, or a mesh. In one embodiment, the inner surface of the cap 7955 isin physical contact with both the first surface 7314 a and the back ofthe mirror element. A front portion 7956 of the covering 7955 bcorresponding to a front portion of the rearview assembly acts as afront electrically-conductive pad of a sensing element. A portion of thecovering 7955 b that wraps around the edge surface 7312 to extend ontothe back 7955 a of the mirror element establishes an electrical contactbetween the electrically-conductive portion 7956 and a back conductivepad 7958 (such as a thin-film layer) disposed at the back of the mirrorelement. The cap 7955 may be configured from a plate of translucentplastic-based material bent so as to fit around the mirror element ofthe rearview assembly and to allow for light channeling, within thethickness of the cap, from a light source 7960 in the back of theassembly towards an indicia/legend carried on an outer surface 7962 ofthe cap. The legend (not shown) may be disposed within the surface 7962(by imprinting, for example) or in a legend-layer 7964 carried on thesurface 7962 so as to overlap with the pad 7956, when viewed from thefirst surface 7314 a. It is appreciated that a front portion of the capthat extends over the first surface 7314 a provides the embodiment witha reliable ESD protection due to a finite thickness of the cap, whichmay be anywhere from several hundreds of microns to a few millimeters.In an embodiment having several sensors, the electrically-conductivecovering is adapted to include several sub-coverings electricallyinsulated from one another, along the inner surface of the cap 7950,with non-conducting areas 7966. In operation, the cap 7955 is removablyput on over the edge surface of the mirror element.

In a “capacitive conductive bezel” type interface, an embodiment ofwhich is schematically shown in FIGS. 80A and 80B, a plastic mountingelement 8002 (such as a bezel or a carrier extending around an edgesurface of the mirror element 7314) having metallic coating, depositedon a portion of the outer surface of the mounting element 8002 and shownwith a dashed line 8002′, is spatially segmented withelectrically-isolated areas 8006 thereby forming electrically conductingpad areas 8004 that the user will touch to activate a correspondingswitch. The mounting element 8002 may also be used as a combinationelement/PCB holder. The isolation pattern 8006 may be defined by lasertreatment, CNC, etching, or masking during deposition of the pattern toseparate pads corresponding to different switches so as to provide forindependent electrical communication between each of the front pad areas8004 and a corresponding conductive pad (shown as 8008) on the back ofthe mirror system. A rear electrical pad area 8008 can be furtherelectrically connected to a PCB 8010 through a spring or an elastomericcontact 8012. For the convenience of the user, a legend or othergraphics (not shown) identifying a particular pad and a correspondingswitch can be incorporated by inscription into the metallic coating8002′ in the area 8004. In this case, to facilitate backlighting of thelegend by an optional light source 8014 such as an LED disposed in theback of the mirror system, the element 8002 may be made of transparentor translucent material. Coupling of light from the source 8014 to thetranslucent mounting element 8002 can be configured directly or with theuse of an auxiliary optical component (not shown), and the mountingelement will channel the coupled light towards the indicia at area 8004.Alternatively, indicative graphics/legends can be placed on the firstsurface (or formed in thin-film layers located within the EC-element)adjacent to corresponding switch areas 8004, or backlit by LCD or maskedLED graphics. In addition, the conductive coating 8002′ may beovercoated with a clear insulating coating layer to protect the finish,or may alternatively be painted to color-match the vehicle interior orsome other components, as instructed by the auto-manufacturer. In aspecific embodiment the front conducting areas 8004 of the mountingelement 8002, a portion of which is shown in FIG. 80C, can be configuredas separate inlays 8010 that are inserted within the mounting element8002 in a fashion similar to that described in reference to FIGS. 70-72.

In addition or alternatively, various already existing and commerciallyused (e.g., in cell phones, PDAs, navigation systems) capacitive orresistive touch screen systems may be used as part of a user interfacein a rearview assembly of the invention.

Various modifications of the embodiments are contemplated within thescope of the invention so as to optimize the performance of the userinterface. For example, in any of the embodiments of a mirror systemthat includes legend/graphics on the first surface and a mountingelement having a lip extending onto the first surface, the mountingelement may be raised slightly above the glass surface so as to reduceor prevent the wearing off of the graphics during handling (such asduring loading into a shipping box and rattling or vibrating in the boxduring shipment). For the same reason, if a legend is placed onto a lipof a mounting element, the legend may be recessed slightly into thesurface of the lip. In a different example, with any of the embodimentsthat use capacitive or field effect sensors, an additional opticalemitter/detector pair may be used to detect that the user's finger isapproaching an interface. Such additional optical sensing pair can actas a ‘gate’ for the computer program product that enables the capacitiveor field effect sensors, thereby increasing the sensitivity of theembodiment by rejecting spurious electrical noise events that may occurduring the time intervals when the user is not using the interface.Increase in sensitivity of detection in this way may facilitate the useof the user interface by a driver wearing gloves, where otherwise thegloves reduce the electrical effect that a finger would have on thesensor. In another embodiment, an electronic circuitry of the rearviewassembly may be configured to utilize the increased sensitivity of asensor in such a fashion as to provide for a time-period, after thesensor of the interface has been activated, during which thelegend/indicia of the sensor remains lit and visible. In a relatedembodiment, the legend may be kept lit dimly (to minimize visualdistraction of the driver), but be illuminated more intensely when thedriver's hand is sensed to be reaching for the legend.

While direct electrical connections have been discussed in reference toFIGS. 77-80, such direct connections are not always required. A flexibleconductor insulated on both sides can wrap from the front surface to theback (similar to the on-glass solutions above). Having both sidesinsulated allows a protective cosmetic layer on the visible surface, butalso allows the back side of the conductor to avoid short circuits tothe exposed conductors at the edge of the element. A larger area springcontact to the electronics can compensate for an indirect connection, asthis will form a capacitive coupling to the sensor.

In all optical or capacitive touch-systems it is preferred to have adirect feedback that the sensor has been activated. Appropriate feedbackcan be provided for the user using optical, audible, or hapticmechanisms. An optical feedback mechanism may include a change ofbrightness or color of back-lit indicia associated with the activatedsensing area of the user interface. An audible feedback mechanism mayemploy a speaker or a piezoelectric device as part of the rearviewassembly, or a direct connection or a network connection to an audiodevice already present in the vehicle. A haptic feedback mechanism caninitiate a slight vibration of the mirror using offset weight electricmotors or an electromagnetic actuator.

In an embodiment employing a user interface of the invention inconjunction with a mirror element having a rounded edge (such asembodiments of FIGS. 68, 69), the first surface overlay of the userinterface may be wrapped around the rounded edge of the mirror elementto create a continuous surface appearance. This may be done with padprinting, or adhesive overlay. Electrical isolation among the sensingareas of the embodiment discussed in reference to FIGS. 73-80 should beequivalent to a resistive separation of at least 10 kOhms, and,preferably, 100 kOhms or greater. Levels of ESD, measured according toindustry standards, should be on the order of at least several keV, forexample 4 kEV, preferably 15 keV, more preferably 20 keV.

It will be appreciated that in another alternative embodiment asensing/switching element of the user interface of the rearview assemblymay be configured with the use of waveguide optics. In particular, thefirst surface of the mirror element may be appropriately overcoated witha slab waveguide layer 8102, as shown schematically in FIG. 81, guidingthe light coupled from a light source 8104 through a coupling means8106. The coupling means 8106 may be configured as any appropriatecoupling means used in waveguide optics (a diffractive element, forexample). When an external object 8110 such as a user's finger makesoptical contact with the surface of the waveguide layer 8102, thewaveguiding is frustrated and light leaks from the waveguide therebyscattering around the point of contact. The scattered light is furtherdetected by an optical detector 8112 (an optical diode, CMOS or othersensor). While light in different spectral regions can be generally usedfor the purposes of the user interface in a rearview assembly of theinvention, a narrow band light source 8104 preferred to reduce potentialinterference with ambient light and increase signal-to-noise ratio ofthe operating embodiment. Other techniques, such as pulsing of the lightsource to differentiate a touch response from ambient light levelsthrough comparison of source on, to source off detected light levels canbe used to actively correct for background and/or stray light andprevent false responses.

In fabrication of the above-discussed embodiments of user interface, aconductive capacitive or resistive switch pattern can be fabricated onor in a pattern carrier (that may be a mounting element such as theelement 7310, for example, or the surface of the mirror element) asfollows:

-   -   The pattern carrier can be coated with a metal or conductive        metal oxide, sulfide, carbide or nitride by vacuum evaporation,        sputtering or other PVD processes. The pattern carrier can be        plated with metal. Metal containing or metalorganic inks can be        applied to the pattern carrier. A conductive polymer such as        polyanaline can be used to form the conductive pattern on or in        the pattern carrier. Other techniques for applying and        patterning conductive materials on substrates (such as those as        described in U.S. Patent Application Publication US2007/0201122        A1 that is incorporated herein by reference in its entirety) may        also be applied. Conductive coatings can be applied in a pattern        or patterned or segmented in a secondary operation using a        laser, chemical etch, water jet, sand blasting or mechanical        cutting, milling or scoring.    -   Conductive metal or conductive plastic inserts can be molded or        fashioned and then incorporated into the molded mounting element        during the injection molding process or placed or pressed into        or onto the mounting element after the molding process. A        two-step injection molding process could be used with a first        step involving molding of conductive portions of the mounting        element from electrically-conductive plastic and another step        involving molding non-conductive portions of the bezel using a        non-conductive plastic. A contact point that engages the switch        could also be a plastic or metal form or tape that contains the        switch conductor or pattern that is adhered to the mounting        element or a surface of the mirror element, preferably in a        periphery of the mirror substrate.    -   A thin metal film, or metal tape, or conductive resin could be        affixed to the inside or outside surface of the mounting element        or the first surface of the mirror element to form the switch        contact point. Segmented conductive switch patterns could be        formatted on such a film or tape prior to adhering it to the        pattern carrier.    -   A conductive paint such as a graphite, carbon nanotube, or        carbon black filled resin, or a resin that is filled with a        transparent or translucent conductive metal oxide particle        (antimony doped tin oxide, aluminum doped zinc oxide, tin doped        Indium oxide, indium oxide, zinc oxide or indium zinc oxide, for        example) can be used for form conductive switch patterns on the        surface of the pattern carrier. An opaque film such as a        carbon-loaded paint can be applied over a translucent or        transparent substrate and patterned to create an icon that could        be backlit by light illuminating such a substrate. The opaque        paint or film could be conductive, or, alternatively, the        substrate could be coated with a transparent conductive material        such as a TCO (transparent conductive oxide), a thin conductive        polymer such as polyanaline. In a specific embodiment, the        substrate could be filled with transparent conductive particles        such as indium oxide, indium tin oxide, zinc oxide, tin oxide,        or low concentration levels of carbon nanotubes or metal fibers        or transparent particles or fibers coated with a transparent        conductive material such as antimony doped tin oxide or indium        tin oxide.    -   In embodiment employing a capacitive type switch, it is        desirable to protect the conductor and electronic circuitry from        static discharge. Such protection is provided by overcoating the        conductor with an insulating layer of plastic, ceramic, paint or        lacquer or recessing the conductor in such a way as to avoid        contact with potential static generating items (like the human        hand or finger).

It is understood that at least one of the transparent and reflectiveelectrodes of surfaces II and III, respectively, could be segmented orpatterned with an icon/legend in an area corresponding to the area ofthe conductive switch or sensor. A peripheral ring could also besegmented and if desired patterned with an icon with or with out abacklight into a conductive switch contact area.

The icon and/or switch circuitry and/or backlight illuminator can beentirely contained in and/or behind the mirror element, in and/or behindthe bezel element or a combination of the bezel and mirror area. A flushbezel could extend a minimum of 2.5 mm around the perimeter of themirror and still meet European minimum edge radius requirements. Atypical perimeter ring is about 5 mm wide. Unless the ring or the bezelis made wider in the switch area, which may be aestheticallyundesirable, a 2.5 mm or 5 mm switch/icon area may not be easilydiscernable by the driver and a 2.5 mm or 5 mm touch landing pad areamay be difficult to accurately locate and touch. Combining both thebezel area and the chrome ring area to enable an enlarged switch areafor the icons, backlight and circuitry enable a more user friendly andfunctional switch system. The icon symbols and backlight could bepositioned in the mirror area and the bezel could have a continuation ofthe icon, or the bezel could be a different color in the icon areaand/or the bezel could be raised in the icon area to enhance switchlocation visibility and functionality. Since finger prints are morereadily visible on a smooth glass surface than on most bezel surfaces,it may be desirable to attract direct finger contact primarily to thebezel area. It is also desirable to cover the contacted area of thebezel and/or glass area with an anti-finger print layer or coating toavoid the visually objectionable accumulation of dirt and finger oils.

Multi-Band Peripheral Ring.

Embodiments of peripheral rings for EC-elements of vehicular rearviewassemblies discussed so far in related art and in this application havea single circumferential band 8210 disposed around a perimeter of thefirst or second surface of the mirror element 8220, as shown in FIG.82A. While this “one size fits all” design has been commonly accepted,it does not address different aesthetic requirements set by differentcar manufacturers. We discovered that configuring an embodiment of aperipheral ring as a multi-band construct may provide a non-obvioussolution to satisfying various aesthetical requirements to appearance ofthe mirror. Generally, in multi-band embodiments of a peripheral ring, aplurality of bands of spectral filter materials are disposedcircumferentially around a perimeter of and on a surface of a mirrorsystem of the invention. While different bands of a peripheral ring maybe configured in a quasi-concentric fashion, thus sharing an origin withone inside the other, a non-concentric configuration and a segmentedconfiguration are also contemplated to be within the scope of thepresent invention. An exemplary illustration of a multi-band peripheralring concept is provided in FIG. 82B, where a top view of a substrate ofan embodiment 8230 of a mirror system is shown to have two peripheralrings 8232, 8234. It is understood that locations within the mirrorsystem, widths of, and materials the bands of a peripheral ring are madeof will depend on a particular application and aesthetic requirements.Moreover, it is understood that different bands may be carried ondifferent structural surfaces of a mirror system, as is described inmore detail below. In a specific embodiment, therefore, a multi-bandperipheral ring may include bands spatially separated along thedirection of incidence of light onto the mirror system. Generally,according to the embodiment of the invention, the aggregate of widths ofbands of a multi-band peripheral ring will not exceed 10 mm, and willpreferably be less than 6 mm, and most preferably less than 4 mm.Relative to the aggregate width of a peripheral ring, a width of a givenband can be between 5 percent and 95 percent, preferably between 10percent and 90 percent, and most preferably between 25 percent and 75percent.

FIG. 83A schematically shows peripheral regions A, B, C, and D of aspecific embodiment 8300 of a mirror system comprising three substrates8310, 8312, 8314 where a multi-band peripheral ring (in this case, aring including up to four bands) may be configured. For simplicity ofillustration, no mounting elements (such as a bezel or a carrier), orconventional optical coatings, or sealing materials are shown. Althoughthe peripheral regions are identified on only one side of FIG. 83A, itis understood that these regions extend in a circumferential fashionaround the perimeter of the embodiment 8300. It is also understood thatconfiguration of a multi-band peripheral ring is not limited to a singlesurface of a particular substrate. Rather, a multi-band peripheral ringmay consist of bands generally disposed on different surfaces (in thecase of embodiment 8300, on either of surfaces I through VI). As shown,e.g., a multi-band peripheral ring 8320 includes four bands 8322, 8324,8326, 8328 disposed respectively on the first, second, third, and fourthsurfaces of the embodiment. Generally, several seals can be used betweenthe substrates forming an EO-element of the embodiment, each sealcorresponding to a particular band of the peripheral ring. For example,as shown in FIG. 83B, an embodiment of a two-lite EO-element 8340 mayhave a peripheral ring 8344 defined by two bands (A and B, correspondingcoatings not shown) and a double seal including seal components 8348,8346 that respectively correspond to the bands A and B.

It is also understood that, in general, some of the substrates may betransversely offset with respect to other substrates and/or be ofdifferent dimensions in order to facilitate, e.g., configuration ofelectrical interconnections and fabrication processes.

In reference to FIG. 83C, a peripheral region may be characterized byspecular or non-specular reflectance, or a reflectance thecharacteristic of which spatially varies with a position in the region.The non-specular characteristic may be formed by choice of materialdeposited on a substrate 8350, such as a frit, or the substrate may bealtered by bead (or sand or other media)-blasting, sanding, rubbing,laser treating, deposition of a transparent layer, a semi-translucentlayer with small particles, or semi-transparent layer that has textureor altered from a smooth surface by other means. A peripheral region mayhave a color determined by various means known in the art such as thinfilm interference, deposition of a colored thin film (absorptioneffects), paint, frit or other means. Alternatively, a coating ortreatment may be absent in a zone and the aesthetics then determined bythe seal or other components within or behind the corresponding band ofa multi-band ring. It is essential that means employed to achievedesired aesthetic parameters does not hinder or frustrate electricalinterconnections required for proper functioning of the embodiment. If agiven treatment, coating or other aesthetic means is employed that isnot compatible with the necessary electrical interconnections thenelectrical interconnections should be appropriately modified and/orreconfigured by, e.g., employing electrically-conductive coatingsinstead of hard-body connectors. These reconfigured components may behidden by the aesthetic means or may be incorporated as part of theaesthetic means whereby the reconfigured electrical interconnectorsadditionally contribute to the appearance of one or more regions of aband.

A specific embodiment of a two-band ring where all bands are disposed onthe same surface can be fabricated either in two cycles (e.g., one bandper cycle) or in a single cycle if thin-film structures of the two bandsare appropriate configured to contain common layers. For example, asschematically shown in FIG. 84A, two bands A and B of a peripheral ring8410 are disposed on the same surface 8412 of a substrate 8414. Areflectance value of a band A is higher than that of a band B. Both thethin-film stack corresponding to the band A and that corresponding tothe band B include a common layer 8416 of a TCO or another dielectricmaterial such as SiO₂, MgO, Ta₂O₅, ZrO₂, MgF₂, ITO, TiOx, CeOx, Sn0₂,ZnS, NiOx, CrO_(x), NbO_(x), and ZrO_(x), W0₃, NiO or Ti_(x)SiO_(y),zinc oxide, aluminum zinc oxide, titanium oxide, silicon nitridedisposed on the surface 8412. Examples of suitable TCO materials includeITO, F:Sn02, Sb:Sn02, Doped ZnO such as Al:ZnO, Ga:ZnO, B:ZnO, and/orIZO. The band A additionally includes a dielectric layer 8418 (selectedfrom the list above for layer 8416) and a metallic layer 8420 (such asilver-gold alloy, silver alloys as described below, chrome, ruthenium,stainless steel, silicon, titanium, nickel, molybdenum, and alloys ofchromium, molybdenum and nickel, nickel chromium, nickel-based alloys,Inconel, indium, palladium, osmium, cobalt, cadmium, niobium, brass,bronze, tungsten, rhenium, iridium, aluminum and aluminum alloys asdescribed below, scandium, yttrium, zirconium, vanadium, manganese,iron, zinc, tin, lead, bismuth, antimony, rhodium, tantalum, copper,nickel, gold, platinum, or their alloys and alloys whose constituentsare primarily those aforementioned materials, any other platinum groupmetals, and combinations thereof. The spectral properties of lightreflected from the band A are determined essentially by the material ofthe layer 8420 and the aggregate thickness of the layers 8416 and 8418.

In comparison with the band A, the band B has an additional layer 8422interdisposed between the layers 8416 and 8418, which is used todramatically reduce the overall reflectance of the band B. Preferably ametal used for layer 8422 should high value of real part of a refractiveindex in order to meet the reflectance objectives of a givenapplication. The real part of refractive index should be above about1.5, preferably above 1.9, and most preferably greater than about 2.1.The value of the imaginary part of the refractive index for a metallicmaterial 8422 for attaining very low reflectance values will vary withthe real refractive index. Lower k values are needed for low realrefractive indices and higher k values will work as the real indexincreases. Preferably, both the real and imaginary parts of therefractive indices should be relatively large. Appropriate metals ormaterials for the thin absorbing metal layer include nickel silicide,chrome, nickel, titanium, monel, cobalt, platinum, indium, vanadium,stainless steel, aluminum titanium alloy, niobium, ruthenium, molybdenumtantalum alloy, aluminum silicon alloys, nickel chrome molybdenumalloys, molybdenum rhenium, molybdenum, tungsten, tantalum, rhenium,alloys of these metals and other metals or materials with both the realand imaginary refractive indices being relatively large. The thicknessof the thin metal layer should be less than about 20 nm, preferably lessthan about 15 nm and most preferably less than about 10 nm. Thepreferred thickness will vary with the reflectance objective andrefractive index of the metal selected for a given application. It isanticipated that at least one thin-film layer of the multi-bandperipheral ring 8410 may extend into the viewing area while the othersare localized in the area of the ring. In addition, UV shielding orblocking may be attained through a combination of material choices andthe optical design of the stack. For example, the dielectric materialsmay be selected which display absorption properties. Specifically, Ti0₂Ce0₂ and zinc oxide are effective UV absorbers. The absorption of the UVlight by these materials may be augmented through a judicious opticaldesign of the coating by using a multilayer stack such as an H/L/Hstack. It is appreciated, that coatings of a particular band of amulti-band peripheral ring that are located on surfaces preceding thesealing materials should preferably protect the sealing materials fromexposure to the ambient UV light. The UV blocking means should reducethe UV transmittance below 5%, preferably below 2.5% and most preferablybelow 1%.

In a non-limiting example, the substrate 8414 is made of glass, and thesurface 8412 is the second surface of the embodiment. The band Bcontains the layer 8416 is about 52 nm of ITO, the layer 8422 is 8.2 nmof Chrome, the layer 8418 is 46 nm of ITO, and the layer 8420 is 50 nmof silver-gold alloy, with gold being at about 7% of the composition.When viewed through the first glass substrate 8414, the band B has aneutral color and a reflectance of 6.9%. The reflected value of a* is3.1 and that of b* is −3.8. The band A, where the Chrome layer 8422 isnot present, has a neutral reflected color and a reflectance of greaterthan about 86.6%. The reflected value of a* is −2.0 and that of b* is0.6. The presence or absence of one layer, therefore, may result in areflectance difference value of greater than about 70% for this coatingstack. Table 9A illustrates how the value of reflectance and color ofreflected light may be altered by the adjustment of the thickness of thelayers. The stack may be altered to change the intensity of thereflectance and/or the color as needed for a given application.Substitution of any or all of the layers with different materials can beused to attain further degrees of freedom in designing a coating for aparticular set of optical requirements. Table 9B shows how the color andtransmittance vary with the thickness of the high reflectance AgAu7xlayer. As a layer is thinned, the transmittance increases with onlysubtle changes to the color and reflectance.

TABLE 9A ITO Cr ITO AgAu7x R a* b* 52 8.2 46 50 6.9 3.1 −3.8 42 8.2 4650 7.0 4.7 2.6 32 8.2 46 50 8.0 3.4 10.9 22 8.2 46 50 9.9 0.5 16.9 128.2 46 50 12.2 −2.2 18.8 62 8.2 46 50 7.9 −1.1 −6.1 82 8.2 46 50 11.7−9.0 −0.3 52 6.2 46 50 7.0 5.1 −15.4 52 4.2 46 50 12.4 4.0 −20.8 52 10.246 50 9.1 0.8 4.7 52 14.2 46 50 15.7 −1.0 8.0 52 8.2 36 50 10.1 3.2 −7.352 8.2 26 50 14.7 3.5 −8.7 52 8.2 56 50 5.1 7.1 −7.4 52 8.2 66 50 5.225.7 −37.3

TABLE 9B ITO Cr ITO AgAu7x R a* b* T 52 8.2 46 50 6.9 3.1 −3.8 0.5 528.2 46 40 6.8 2.8 −2.6 1.1 52 8.2 46 30 6.5 2.3 −0.1 2.6 52 8.2 46 205.9 1.7 4.0 6.5 52 8.2 46 10 6.1 2.3 4.1 16.8

The reflectance value of light reflection in the area of the “bright”band A is dominated by the reflectance of the metal positioned away fromthe viewer. If the silver-gold alloy from the previous example isreplaced with chrome and the other layers are re-optimized (thethickness of the layer 8416 of ITO is 53 nm and the thickness of thelayer 8418 of ITO is 57 nm), then a neutral appearance in reflection isstill attained but the reflectance of the band A is reduced to about50%. If, instead of silver-gold alloy, Ruthenium is used in the layer8420, the reflectance is about 57%, Rhenium yields about 38%, Molybdenum45%, Copper 54%, Germanium 29%, Tantalum 39%, and other metals willyield other reflectance values depending on their properties. Thisembodiment is not limited to this set of metals and other metals(described elsewhere in this document) with different reflectance valuesand hues may be used and are within the scope of this art. Moreover,multiple metals may be employed where the thickness of each layer isadjusted to attain the reflectance and hue for a given application. Forexample, in the case where a silver alloy is used as the second metallayer, a high reflectance is attained. If it is important to have lowerreflectance and opacity one can include an additional metal or metalsbetween the silver alloy layer and the viewer to attenuate the intensityof the reflectivity. The additional layer may provide other benefitssuch as adhesion, corrosion protection or any other of beneficialproperties. Typically, the reflectance will decrease as the thickness ofthe additional layer(s) is increased, eventually reaching thereflectance of the additional metal when the thickness reaches acritical thickness. Alternatively, if only the reflectance is to bereduced, and transmittance is not needed to be low (see embodimentsbelow) the thickness of the metal, such as silver gold alloy, can bereduced thus decreasing the reflectance and increasing thetransmittance. In other embodiments where lower reflectance is desiredin combination with low transmittance, the additional metal or absorbinglayer may be placed behind the reflector metal, relative to the vieweron the outside portion of the rearview assembly. In this manner, thethickness of the reflecting metal layer may be adjusted as needed toattain the desired reflectance value and the thickness of the additionallayer behind the reflector metal can be adjusted as needed to attain thedesired transmittance value. The metal above or below the silver layermay be selected to be, e.g., chromium, stainless steel, silicon,titanium, nickel, molybdenum, and alloys of chrome, and molybdenum andnickel, nickel chromium, molybdenum, and nickel-based alloys, Inconel,indium, palladium, osmium, tungsten, rhenium, iridium, molybdenum,rhodium, ruthenium, tantalum, titanium, copper, nickel, gold, platinum,and other platinum-group metals, as well as alloys the constituents ofwhich are primarily aforementioned materials. Combinations of metallayers are selected so that the reflectance may be set between about 45and 85% with the transmittance between about 45 and 5%. Preferably thereflectance is between 55% and 80% with transmittance intensity betweenabout 35% and 10%.

It is recognized that appropriate optimization of a thin-film stack of aparticular band of the peripheral ring will affect the opticalproperties of the band. In a specific embodiment, it may be preferred toinclude a layer of a quarter wave thickness and a refractive indexintermediate between the first TCO or dielectric layer and therefractive index of the substrate, e.g., glass or other transparentmedia between the substrate and the TCO layer. Flash overcoat layers ofmaterials mentioned in U.S. Pat. No. 6,700,692 may also be incorporatedinto the above described designs. Depending on the thickness and opticalproperties of the materials chosen for the flash layer(s), adjustmentsmay be needed to the underlying stack to maintain a similar degree ofmatch or mismatch between the relatively opaque region and thetransflective region(s).

In order to have a noticeably different appearance between the bands ofa multi-band peripheral ring, when required, the correspondingbrightness values should differ by at least 3 L* units. Preferably thebrightness values of the bands will differ by greater than about 10 L*units, more preferably by about 20 L* units, even more preferably bymore than about 50 L* units. The low reflectance band of the peripheralring should be less than about 60%, more preferably less than about 30%,even more preferably less than 20% and most preferably less than about12%. The value of reflectance of the high-reflectance band should begreater than about 40%, preferably greater than about 50%, even morepreferably greater than about 60% and most preferably greater than about70%. The difference in reflectance values between the two bands may be adifference in magnitude of the specular reflectance or it may be adifference in the specular and non-specular reflectance. In addition oralternatively, the two bands have a difference in color or hue. Thecorresponding difference in C* values (measured in reflectance) shouldbe greater than about 5 units, preferably greater than about 10 units,more preferably greater than about 15 units and most preferably greaterthan about 25 units. The color difference may be combined with changesin either reflectance magnitude, reflectance type (specular ornon-specular) or some other aesthetic effect such as surface texturing.

FIGS. 84B through 84D present different variants of the embodiment ofFIG. 84A. The stacks A and B in FIG. 84B, for example, do not have thefirst TCO or dielectric layer disposed on glass as shown in FIG. 84A.(If the first TCO covered the entire surface, then its removal wouldresult in a lower sheet resistance in the viewing area and potentiallyincreasing the switching or darkening time.) The reflectance in the twobands and color of ambient light incident from the first surface andreflected by the bands in the +z direction are relatively unaffected bythe removal of the first ITO layer. The color and reflectance may betuned or adjusted as described above but with one less degree offreedom. The thickness of the layers, as described above, can be alteredto change the color. The ease of color tuning is reduced when a layer isabsent. The embodiment of FIG. 84B demonstrates a basic structure of atwo-band peripheral ring having a high-reflectance band and alow-reflectance band. FIG. 84C, in comparison with FIG. 84B, has anadditional TCO or dielectric layer 8416 as the layer distal to theviewer. This layer may be present in the ring area only or it may extendinto the viewing area. This layer may be present to protect the metallayers or improve the adhesion to the seals or provide an alteredelectrical contact to the buss or electro optic material. FIG. 84D, incomparison with FIG. 84A, shows an additional TCO or dielectric layer8426 on top of the layers 8420 in both bands A and B. The layer 8426 canadd properties similar to those as described in reference to FIG. 84C.Furthermore, if the outermost layer is a TCO then it will lower thesheet resistance in the viewing area or modify the optical thickness andthe resultant color in the bright and predominantly, the dark state ofan EC as described in Our Prior Applications. A TCO layer used withinthe area of a peripheral ring serves a purpose of attaining the desiredreflectance and color, and when it extends beyond the peripheral ring italso serves as a transparent electrode for the EC-cell, the conductivityof which may be modified by additional TCO layers. The thickness of aTCO layer in various positions in the stack may be optimized tocoordinate the desired color in the ring positions and the viewing areain the bright and dark state. Additional TCO layers that extend beyondthe ring area may be added on top of the ring layers to add additionalconductivity to the electrode.

It is appreciated that when a multi-band peripheral ring is disposed onthe first surface instead of the second surface, the order of the layersshould be reversed (with respect to the viewer) in order to preserve theoptical properties of the band discussed in reference to FIGS. 8A-8D.

As demonstrated, configuring bands of a multi-band peripheral ring tohave common thin-films layers makes the multi-band ring more suitablefor manufacturing. One technique to facilitate a single-cyclemanufacturing is to use simplified masking and registration of multiplemasks. There are several masking options available for deposition of themulti-band coating depending on the type of coater used (e.g., in-lineor turret). FIG. 85 shows one possible mask construction including anedge mask 8510 and the plug mask 8512. It is understood that othermasking or fabrication options are viable for making these products andthe invention is not limited to this particular example. In a turrettype coater the substrate 8514 to be coated is held stationary relativeto the target with or without masking present. The target or otherdeposition means are activated and the substrate is coated in areas notmasked. The part then cycles to another deposition bay where the processis repeated with the same or different masking arrangement.

The number of deposition bays is selected based on a given application.In order to produce the construction described in FIG. 8 a the substratewould be arranged with only the plug mask so that both bands A and Breceive the coating. Optionally, the plug mask 8512 may be absent sothat the layer 8416 covers the entire surface of the substrate inaddition to the regions A and B. Further, the edge mask 8510 is used toprevent the deposition of the layer 8422 in the region A and the plugmask 8512 is used to limit the deposition of layer 8422 in the region B.The layer 8418 would be disposed similarly to the layer 8416. In thecase of the layer 8420, only the plug mask 8512 would be used. It isunderstood that other masks may be added or subtracted as needed toachieve the proper thickness and locations of the layers on the part andis within the capabilities of one skilled in the art.

Generally, a dark material such as an appliqué may be disposed at theback of the mirror element. In embodiment including two lites of glass,such appliqué may be disposed on or behind the fourth surface and doesnot need to terminate at an edge of peripheral region B. For aestheticreasons, such as matching the color of the vehicle interior, theappliqué may be of a color other than black. In other embodiments it ispossible that embedded light sources with means such as matte finishand/or anti-reflective coatings (to decrease the visibility when off)are incorporated within region B. If the band B has low reflectance(and, accordingly, high transmittance) and the adjacent band A has highreflectance (and low transmittance), the light from the embedded lightsources will traverse the mirror element towards the viewersubstantially only through the band B because the band A and the centralportion of the mirror have a relatively low transmittance.Alternatively, the light can originate from the edges of the glass orfrom another source direction and transmit through zone B eitherrelatively collimated or with a spread of angles. The light source(s) ofthe embodiment may be arranged and integrated with other functionalitiesfor a variety of purposes. In one embodiment the light sources indicatean approaching vehicle in the blind spot of the driver by scrolling fromthe top middle to the top left for a vehicle on the left and from thetop middle to the top right for vehicles in the right blind zone. Thelight sources could also be used as a compass indicator with light atthe top middle and bottom of the mirror corresponding to N,S,E,W. withadditional points as desired. The light source(s) could also be used asa make-up or vanity mirror that might only allow activation if thevehicle were in park. Decorative functions or themes such as a holidaytheme of red and green lights could also be incorporated into theperipheral ring lighting. Additionally, layers in a particular band of aperipheral ring may have non-uniform thickness as needed to attainparticular functional or aesthetic effects. This can be seen in FIG. 86,where a band in region B is divided into two portions designated as B1and B2 and generally having different reflectance and transmittancevalues. The two regions in zone B can be comparable to stacks of theprior or related art and as described of the novel coatings andstructures defined in this patent. The transmittance in the lowreflectance and high reflectance zones, in some embodiments, is lessthan about 5%, preferably less than about 2%, more preferably less thanabout 0.5% and most preferably less than about 0.25%. This is so thatthe seal is protected from UV light which can degrade the integrity ofthe seal, as described above. If, however, it is important to conveyvisual information through the seal area, the transmittance may berelatively high as described above.

As already mentioned, in a specific embodiments it may be beneficial tohave all or part of the multi-band peripheral ring be at least partlytransparent in the visible, UV or NIR spectra. For instance, a glaresensor can be positioned behind the ring when a band of region A and/orB has sufficient transmittance in the relevant part of theelectromagnetic spectrum and the seal (if present in a particular band)also has the necessary transmittance. Here, teachings of U.S. Pat. Nos.7,342,707; 7,417, 717; 7,663,798 (different means for attaining atransflective coating, including a graded transition) and U.S. patentapplication Ser. Nos. 11/682,121; 11/713,849; 11/833,701; 12/138,206;12/154,824; 12/370,909 (transflective stacks, including means tominimize the color difference between multiple zones of a mirror elementand to increase durability) can be advantageously utilized. A number ofdifferent means may be employed to produce a transflective ring. Forinstance, a band of a multi-band peripheral ring may comprise a thinmetal layer, a semiconductor material such as silicon, or may becomposed of a dielectric multilayer stack. Silver or a dielectricmulti-layer is most applicable when both relatively high transmittanceand reflectance is desired. The semiconductor layer may comprise Siliconor doped silicon. Small amounts of dopants may be added to alter thephysical or optical properties of the Silicon to facilitate its use indifferent embodiments. The benefit of a semiconductor layer is that itenhances the reflectivity with less absorption compared to a metal.Another benefit of many semiconductor materials is that they have arelatively low band gap. This equates to an appreciable amount ofabsorption at the UV and blue-to-green wavelengths and hightransmittance in the amber/red parts of the spectrum is needed forsensors and the like. The preferential absorption of one or more bandsof light lends the coating to have relatively pure transmitted color.The high transmitted color purity equates to having certain portions ofthe visible or near infrared spectra with transmittance values greaterthan 1.5 times the transmittance of the lower transmitting regions. Morepreferably the transmittance in the high transmitting region of amulti-band transflective peripheral ring will be more than 2 times thetransmittance in the low transmitting region of a multi-bandtransflective peripheral ring and most preferably more than 4 times thetransmittance in the low transmitting region. Alternately or inaddition, the transmitted color of a transflective band of a multi-bandperipheral ring should have a C* value greater than about 8, preferablygreater than about 12 and most prefer ably greater than about 16. Othersemiconductor materials that result in transflective coatings withrelatively high purity transmitted color include SiGe, InSb, InP, InGa,InAlAs, InAl, InGaAs, HgTe, Ge, GaSb, AlSb, GaAs and AlGaAs. Othersemiconductor materials that would be viable would be those that have aband gap energy at or below about 3.5 eV. In an application wherestealthy characteristics are desired and a red signal is used then amaterial such as Ge or an SiGe mixture may be preferred. Ge has asmaller band gap compared to Si and this resulting in relatively lowtransmittance levels within greater wavelength range, which facilitatesthe “hiding” of any features behind the mirror. If a uniformtransmittance is needed then it would be advantageous to select asemiconductor material that has a relatively high band gap.

FIG. 87A shows an example where a portion C of a two-band peripheralring is transflective, while another portion includes theabove-described bands A and B. Optionally, the portion of the ringoutside of portion C may consist of a single band A, produced with thedesired aesthetics for a given application. The transflective portion Cmay cover a part or the entire peripheral ring as needed for a givenapplication. In FIG. 87B, the transflective portion C is relativelysmall and a sensor 8710 is placed behind it. The sealing element (notshown) may be positioned in the portion C such that it does not blockthe light from reaching the sensor or, optionally, the seal may beformed by using a clear seal. The transitions between the opaque zone Aand the transflective zone C may be formed using means taught in“multi-zone mirror” so that there is no discernable line or interfacebetween the two zones. Some examples of transflective thin-film stacksfor use with corresponding opaque zone are listed in Table 9c. ExamplesA through I in Table 9c all include a specific embodiment of atransflective surface II perimeter ring stack. Examples A, B, C and Galso include an opaque equivalent. In each case, the stack is identifiedas being on surface II with the glass substrate listed as the firstentry. Each subsequent entry represents a layer applied to surface 2subsequent to the layer listed above it. The opaque versions aredesigned to match the color and reflectance of the transflectiveperimeter ring stack as closely as is reasonable for embodiments whereit is desirable for only a portion of the perimeter ring to betransflective with the remainder being essentially opaque. The thicknessof each layer is shown in nanometers. The transmittance (%), reflectance(%) and color (a*, b*) are also given for each example. In each caseother than A, the transition between the transflective stack and theopaque stack can be abrupt, which will yield a reasonably stealthytransition, or the transition can be graded to yield a very stealthytransition. Example A would likely require a graded transition in orderto appear stealthy. Both approaches are taught in detail in U.S.2009/0207513. FIG. 87C shows the reflectance and transmittance ofexample H. The spectra show low transmittance in the UV portion of thesolar spectrum and a relatively high transmittance in the visiblespectrum. Preferably the UV transmittance is less than about 15% of thevisible transmittance, preferably less than about 10% of the visibletransmittance and most preferably less than about 5% of the visibletransmittance.

TABLE 9c Examples of surface 2 transflective thin film stacks, some withmatching opaque equivalents. Transflective: Opaque: Example Layer nm % T% R a* b* Layer nm % T % R a* b* A Glass 5.1 64.9 0.4 4.8 Glass 0.8 73.2−0.4 1.8 Al90/Si10 23.5 Al90/Si10 40.0 ITO 145.0 ITO 145.0 B Glass 6.546.2 −1.8 −3.8 Glass 0.7 57.1 −1.3 −2.5 Cr 14.0 Cr 35.0 ITO 145.0 ITO145.0 C Glass 5.5 52.8 −1.1 0.3 Glass 0.5 63.7 −1.0 2.7 Brass 10.0 Brass10.0 Cr 13.0 Cr 35.0 ITO 145.0 ITO 145.0 D Glass 10.1 34.0 4.5 −4.6 Ti35.0 ITO 145.0 E Glass 8.2 40.9 4.2 0.2 Brass 5.0 Ti 35.0 ITO 145.0 FGlass 8.8 64.9 2.2 2.5 7X 25.0 Ru 5.0 ITO 145.0 G Glass 21.5 65.4 0.43.1 Glass 2.0 65.7 0.7 0.0 ITO 72.7 ITO 72.7 7X 14.0 7X 14.0 Ni 0.0 Ni30.0 7X 9.3 7X 9.3 H Glass 12.9 56.2 −5.7 −0.1 ITO 115 Cr 5 Ru 5 Si 115I Glass 31.4 66.2 −1.7 0.6 TiO2 54.5 SiO2 91.4 TiO2 54.5 SiO2 91.4 TiO254.5 ITO 72.1

In another embodiment of a peripheral ring, as shown in FIG. 88A, atransflective portion C of a two-band (A and C) peripheral ring mayinclude indicia or icons 8810. The indicia may be invisible under normalconditions and only become observable when needed. In other embodimentsit may be preferable to have the indicia visible under normalconditions. In yet another embodiment, the indicia may become observablevia voice activation, proximity sensors or other means. In theembodiment where the ring is transflective, the openings 8812 forindicia or icons 8810 may be formed in a relatively opaque coating 8814located behind a transflective coating 8816 on one of the surfaces of acorresponding substrate 8820, as shown in FIGS. 89B and 89C.Alternatively, the openings 8812 for indicia or icons may be present ona separate masking element 8824 located behind the transflective coating8816 of the peripheral ring and only become visible when the light unit8830 of the rearview assembly is activated, see FIG. 88D.

Optimization of Choice of Materials for Reflectance Enhancement.

Earlier in this application described was a means of increasing thereflectance of a portion of the peripheral ring with the use of highreflectance (HR) metallic layers by disposing them directly on a TCO,dielectric or another other layer, directly on glass substrate, or anoptional adhesion-enhancement layer that may be present on the glasssurface. The high reflectance metals appropriate for such a purpose aredefined based on their bulk reflectance properties and, to a largeextent, their intrinsic color. Preferably the high reflectance metalshould have a neutral color so that ambient light reflected from theresulting peripheral ring substantially matches in color the lightreflected from the central portion of the mirror element. Earlierexamples illustrated in Tables 1a through 1e showed how the use ofdifferent metallic layers and thickness of those layers in a peripheralring can affect the color match between the ring and the central portionof the mirror. Table 10 below illustrates the reflectance valuescharacterizing various metallic 3 nm-thick layers deposited on andviewed through the glass substrate and comparisons of these reflectancevalues and color of reflected ambient light with that of the glasssubstrate itself.

TABLE 10 Delta Material Reflectance a* b* Delta R Delta a* b* glass 7.9−0.2 −0.6 3 nm cobalt 5.8 −0.1 0.0 −2.2 0.1 0.6 3 nm chrome 6.3 −2.0−2.3 −1.7 −1.8 −1.7 3 nm iridium 6.7 −0.9 0.7 −1.3 −0.8 1.2 3 nm Mo 5.4−2.9 −1.2 −2.6 −2.7 −0.7 3 nm Ag with 7% 11.0 1.3 4.1 3.1 1.5 4.6 Au 3nm Au 7.8 0.8 9.2 −0.2 0.9 9.8 3 nm Cd 8.5 −0.5 −0.4 0.5 −0.3 0.2 Cu 3nm 6.9 5.1 3.7 −1.1 5.3 4.3 3n 5050 SnCu 6.7 −0.1 0.6 −1.2 0.0 1.2 3 nm5050 CuZn 7.5 1.0 4.7 −0.4 1.2 5.3 3 nm Nb 4.2 −0.1 −1.3 −3.7 0.1 −0.7 3nm Pd 6.5 0.3 0.6 −1.4 0.5 1.1 3 nm Ru 10.5 0.4 −0.1 2.5 0.6 0.4 3 nm Pt5.5 0.2 0.5 −2.4 0.3 1.0 3 nm Rhenium 5.8 −1.5 −4.7 −2.2 −1.3 −4.1 3 nmRh 7.7 0.7 0.3 −0.3 0.9 0.9 3 nm Ta 5.1 −0.2 −0.2 −2.9 0.0 0.4 3 nm Ag10.3 1.2 3.7 2.4 1.4 4.3 3 nm Al 19.9 0.2 3.5 11.9 0.4 4.0

Table 11 illustrates values of real and imaginary parts of therefractive indices at 550 nm for various metals.

TABLE 11 Metal n @550 nm K @550 nm Ag 0.136 3.485 AgAu7x 0.141 3.714 Al0.833 6.033 Al:Si 60:40 3.134 4.485 Al:Si 90:10 1.244 4.938 Al:Ti 50:502.542 2.957 Al:ti 70:30 2.885 3.392 Au 0.359 2.691 Cd 1.041 4.062 Co2.053 3.826 Cr 2.956 4.281 Cu 0.958 2.577 CuSn 1.871 4.133 CuZn 0.5872.854 Ge 3.950 1.975 Ir 2.229 4.314 Mo 3.777 3.521 Nb 2.929 2.871 Ne1.772 3.252 Pd 1.650 3.847 Pt 2.131 3.715 Re 4.253 3.057 Rh 2.079 4.542Ru 3.288 5.458 Ta 3.544 3.487 Ti 1.887 2.608 V 3.680 3.019 W 3.654 3.711Zn 1.117 4.311 Zr 1.820 0.953

It is known by one skilled in the art that refractive index of a givenmetal and dispersion of refractive index are dependent on the processand deposition parameters used to produce the coating and that adeposition processes can be optimized to slightly modify opticalconstants of a particular metal. The difference between materialproperties of thin metallic films as compared to bulk (or thick film)metals has limited the use of metals, at least in applications relatedto automotive rearview mirror assemblies, to substantially thickmetallic layers where the optical properties are more predictable andconsistent with the “bulk”-metal behavior. The data of Table 10 suggestthat, generally, metals would not be optimal materials for increasingthe reflectance of other metals or, if such a possibility exists, thenat least the increase in reflectance may not be accompanied with aneutrality of color. As a result, the use of thin metallic film forreflectance-enhancement of multi-layer stacks has been substantiallylimited.

The following describes an attempt to formulate a generalized approachof determining which metals can be reliably used for enhancing thereflectance of a simple structure comprising a chosen metallic material(referred to hereinafter as a base metal) carried by a thick glasssuperstrate that acts as incident medium. In particular, suchreflectance-enhancing (RE) metallic layers are considered to be disposedon a second surface of the thick glass superstrate and the base metal.The change in reflectance is being considered in light incident onto themetallic layers through the glass superstrate and reflected back to thefirst surface. The generalized approach is determined based onconsidering the relationships, between the real and imaginary parts ofrefractive indices for several base metals and several 3 nm thickRE-metallic layers, that allow for increase in reflectance at issue. TheD65 Illuminant and 10 degree observer color standards were used for allcalculations.

Example 1

Environmentally stable and low-cost Chromium is used as the base metal.A thin film program was used to calculate the resultant color andreflectance of light for the different 3 nm-thick RE-metallic layers.The results are summarized in Table 12.

TABLE 12 Structure Reflectance a* b* Reference 52.3 −1.9 −0.7 (Glass +chrome base layer) Reference + RE-layer made of . . . cobalt 54.3 −1.60.5 chrome 52.3 −1.9 −0.7 iridium 54.8 −1.8 0.6 Mo 50.1 −1.4 1.5 Ag with7% Au 57.4 −1.7 −0.3 Au 54.7 −2.1 2.1 Cd 56.7 −1.7 −0.6 Cu 54.4 −1.3 0.3SnCu 5050 55.2 −1.7 0.2 CuZn 5050 55.0 −1.7 0.9 Nb 50.9 −1.4 1.4 Pd 55.2−1.6 0.3 Ru 54.9 −1.6 0.2 Pt 53.9 −1.6 0.8 Rhenium 47.6 −1.2 4.3 Rh 55.7−1.4 0.4 Ta 50.2 −1.6 2.1 Ag 56.9 −1.7 −0.2 Al 62.2 −1.5 −0.9 Al:Si60:40 53.2 −1.6 0.3 Al:Si 90:10 58.3 −1.7 −0.3 Al:Ti 50:50 51.8 −1.7 0.9Al:Ti 70:30 51.7 −1.6 1.3 Ge 47.4 −1.9 −1.1 Ni 53.8 −1.7 0.8 Ti 52.7−1.8 0.4 W 49.2 −1.7 3.1 V 49.4 −0.7 0.8 Zn 56.7 −3.1 −1.1 Zr 51.7 −1.9−0.7

FIG. 89A graphically shows a corresponding change in reflectance of theconsidered structures of Table 12 with n (real part of the index of theRE-metal, x-axis) and k (imaginary part of the index of RE-metal,y-axis). The dots on the graph represent the reflectance values for thedifferent RE-metals. The contour lines represent contours ofiso-reflectance. The dashed line represents a contour approximatelydescribing the reference structure of Table 12. The use of metals havingn and k values falling to the right of the dashed reference line asRE-metals leads to decrease of the reflectance value of the structure,while the use of metals with n and k values falling to the left of thedashed reference line leads to the overall increase in reflectance.Based on the dashed reference iso-contour, the condition on RE-metalsassuring the increase in reflectance of the reference structure of Table12 is k−1.33n≧0.33.

It is understood that when a metal satisfying the above equation is usedas a RE-layer added to the reference structure, the increase of theRE-layer thickness above 3 nm will only further increase the overallreflectance. Generally, therefore, the thickness of the RE-metalliclayer should be greater than about 1 nm, preferably greater than about 3nm, more preferably greater than about 5 nm and most preferably greaterthan about 10 nm. As noted above there may be other layers between thereflectance enhancement layer and the substrate.

Similarly, two additional examples have been considered: Example 2 withCuSn alloy (50:50) as the base metal, and Example 3 with Ta as the basemetal. Table 13 and FIG. 89B present results for Example 3, while Table14 and FIG. 89C summarize the results for Example 4.

TABLE 13 Structure n k R a* b* Reference (Glass + 1.871 4.133 60.0 −0.43.2 CuSn base layer) Reference + RE-layer made of . . . AgAu7x 0.1413.714 65.4 −0.4 3.3 Al:Si 90:10 1.244 4.938 64.1 −0.5 2.7 Cr 2.956 4.28156.2 −0.2 1.5 Ge 3.950 1.975 50.3 0.1 2.3 Ru 3.288 5.458 56.7 −0.6 2.3Ta 3.544 3.487 52.4 0.2 5.4 Ti 1.887 2.608 58.1 −0.3 4.0 V 3.680 3.01957.3 0.4 2.5 Zr 1.820 0.953 58.4 −0.4 3.0

TABLE 14 Structure n k R a* b* Reference 3.544 3.487 46.6 0.2 3.7(Glass + Ta base metal) Reference + RE-layer made of . . . AgAu7x 0.1413.714 51.9 0.1 4.0 Al:Si 90:10 1.244 4.938 53.6 −0.1 3.1 Cr 2.956 4.28149.2 −0.3 1.9 CuSn 1.871 4.133 50.6 0.0 3.4 Ge 3.950 1.975 42.9 0.1 1.0Ru 3.288 5.458 51.3 −0.2 2.1 Ti 1.887 2.608 47.7 0.2 3.6 V 3.680 3.01947.6 0.4 2.2 Zr 1.820 0.953 46.3 0.1 3.2

The reflectance iso-contour for Example 2 in FIG. 89B is at 60%reflectance and is described by the equation k=3.919*n−3.6129. Thehigher reflectance is attained when the following condition is met:k−3.919*n≧−3.6129. The reflectance iso-contour for Example 3 in FIG. 89Cis at 46.6%. The equation for this contour is estimated to bek=0.8452*n+0.1176. The condition for enhanced reflectance isk−0.8453*n≧0.1176.

Further, values of slopes of the above three linear dependences andvalues of k corresponding to n=0 (the intercept of the y-axis) wereplotted against values of n to obtain FIGS. 90A and 90B, where discreetresults are fitted linearly (FIGS. 90A and 90B) and quadratically (FIG.90B). The obtained fits are as follows: slope=7.362−1.911*n; linearlyfit intercept=2.413*n−7.784 and the quadratically fitintercept=−23.7+15.23*n−2.401*n². Based on these generalized fits, theestimate of the coefficients of the equation necessary to define theoptical constants for the RE-metals can be performed.

The appropriate materials for reflectance enhancement taught above aredefined for systems with a relatively high refractive index superstrate.Float glass or plastic, for instance, have a relatively high refractiveindex relative to air. That is why the thin metals, as taught above, actas anti-reflection layers when in contact with, and viewed through, ahigh index superstrate. A similar behavior occurs with other superstratematerials such as Electrochromic fluid or gel. The EC fluid or gel has ahigh refractive index relative to air and that is why the reflectance ofan EC element is substantially lower than the reflectance of the mirrormetalized glass. A mirror system described herein, comprising a firstlite of glass with a first and second surface, a transparent electrodearranged on the second surface such as ITO, a second lite of glass witha third and fourth surface, a reflective metal system comprising a firstlayer of chrome on the third surface and a second layer of ruthenium onthe chrome layer with a perimeter seal that forms a chamber between thetwo lites of glass. The chrome/ruthenium coated glass has a reflectanceof about 70% when measured with air as a superstrate and about 57% inthe EC configuration. Much of the reflectance drop is due to the highrefractive index of the EC fluid being in contact with the rutheniumlayer.

Various metals have been taught in the art that exhibit high reflectanceand are electrochemically stable in an Electrochromic device. Forinstance, silver alloys, such as silver gold, or other noble metals suchas platinum or palladium have been described in the Electrochromic art.There have been a limited number of viable metals taught in the art dueto the combined requirement of high reflectance and electrochemicalstability. For instance, as taught in U.S. Pat. No. 6,700,692, themetals must have a sufficient electrochemical potential to functionsatisfactorily as an anode or cathode in a fluid based electrochemicaldevice. Only noble metals, Au, Pt, Rh, Ru, Pd have demonstratedsufficient reflectivity and electrochemical stability. The prior artreferences that alloys may be viable but no methods are described thatcan be used determine which alloys may be viable from a reflectanceperspective. The formula described above can be used to target theviable noble metals alloys that will increase the reflectance of a basemetal in an electrochromic device. The structure of the coatings on the2^(nd) lite of glass would be glass/base metal/reflectance enhancementnoble metal alloy/viewer. The formula taught above demonstrates a way toselect improved metal alloys that include noble metals that are suitablefor Electrochromic devices.

The previous teaching around the use of noble metals in Electrochromicdevices relies on the combination of electrochemical stability and highreflectivity that the noble metals possess. Other metals, other thanaluminum, haven't been proposed because they do not have sufficientreflectivity and electrochemical stability. Aluminum has been proposed,but has not been realized practically as a third surface electrodebecause it does not have sufficient electrochemical stability in a fluidbased EC device. Other metals or alloys have not been employed inElectrochromic devices because it is believed that they do not have thenecessary reflectivity and electrochemical stability. The discoverydescribed above, where a metal with a newly defined refractive indexcharacteristic can increase the reflectance of a base metal, enables anew class of metals, alloys and materials to be considered for use inElectrochromic mirrors and devices. The REM should increase thereflectance of the base metal by at least 2 percentage points, i.e., 50to 52%, preferably increase the reflectance by about 5%, more preferablyby about 7.5% and most preferably by greater than about 10%.

The refractive index characteristic is insufficient because there is nocorrelation between this characteristic and the electrochemicalpotential characteristics. If the REM is doped or alloyed with a noblemetal it would fall within the improvements for the noble metal alloysdefined above. The REM may be employed in a thin film stack in anintermediate location by the application of a capping layer withsufficient electrochemical properties. The capping layer may be a noblemetal, or alloy of a noble metal or may be a transparent conductionoxide such as ITO, IZO or the like described elsewhere in thisapplication. The capping layer, if it does not have a refractive indexas defined with our new equation will reduce the reflectance of the REM.This has obvious disadvantages and therefore the capping layer must berelatively thin otherwise there will be no reflectance increase attainedfrom the REM. The capping layer, if it does not meet the criteria forreflectance enhancement, will decrease the reflectance to a greaterdegree in an opposite manner to which the refractive index will increasethe reflectance. Therefore, layers with large real parts of therefractive index and low parts of the imaginary refractive index willdecrease the reflectance the greatest. Obviously, as taught above therelative change in the reflectance is a function of the relativerefractive indices between the two metals. The amount of change for agiven thickness of film (3 nm in FIGS. 1, 2 and 3) can be estimated fromthe newly developed formulas. Preferably, a capping layer with noblecharacteristics should reduce the reflectance by less than 5%, morepreferably less than 2.5% and most preferably less than 1.5%. Thethickness of the capping metal layer with noble characteristicsnecessary to maintain these reflectance changes will vary with therefractive index properties of the REM but should be less than about 4nm, preferably less than about 3 nm and most preferably less than about2 nm. A TCO-based capping layer may meet the reflectance requirements atup to a 30 nm thickness.

Silver Alloys for Corrosion Resistance.

High reflectivity of silver makes this material particularly useful formirrors and EC-mirrors. Specifically, in applications where the centralportion of the mirror inside the peripheral ring has reflectance valuesgreater than 60%, more preferably greater than 70% and most preferablygreater than about 80%, and where matching of the ring's reflectancevalue to that of the central portion of the mirror is required, it isadvantageous to use high-reflectance Ag-based materials for theperipheral ring instead of Chrome and noble metals. The requirements fora peripheral ring application are more stringent than those for a 3^(rd)surface reflector because all portions of the peripheral ring arevisible to the user while portions of the 3^(rd) surface reflector nextto electrical buss connections are hidden from the view and, therefore,allow for minor metal degradation and corrosion. Therefore, not onlymust the seal and electrical connections be maintained in environmentaltests but the visual appearance of the coating must be maintained.Silver has limited corrosion resistance and electrochemical stabilitythat originally limited its use as a third surface reflector electrodein EC-mirror systems. Dopants and stabilizing layers have been proposedand commercialized that give silver acceptable resistance to both CASStesting from a chemical durability perspective and electrochemicalstability from a device electrical cycling perspective. Acommonly-assigned U.S. Pat. No. 6,700,692 taught that platinum groupmetals, such as Pt and Pd along with Au were the preferred dopants forAg, and that noble metals such as Ru, Rh and Mo were preferred materialsfor stabilization layers. No specific examples were given, however, thatpertain specifically to the dopants alone and their effect on chemicalor environmental durability of Ag. Prior art simply implied that theplatinum group metals within the silver layer provide theelectrochemical stability while the layers below (and/or above) thesilver provide the CASS resistance.

We discovered non-obvious solutions that allow for substantialimprovement of the durability of Ag and Ag-alloys through the use ofalternate dopants and without stabilization layers. The basic structureof an underlying embodiment included Glass/125 nm ITO/50 nm silver orsilver alloy/15 nm of ITO. Fully assembled EC-elements were run throughthe CASS testing and steam testing, while epoxy-sealed EC-cells withoutEC-medium were subjected to blow tests. Testing conditions were asfollows: CASS testing was performed according to recognized industrialstandards. In the steam tests the parts are held in an autoclave atapproximately 13 psi and 120 C in a steam environment and checked once aday until failure. In the case of CASS two failure modes arenoted—coating degradation and seal integrity. In the case of the steamtests, only seal failure is reported. In the blow test, a hole isdrilled in a part, the part is gradually pressurized until failureoccurs, and the pressure at failure is noted. A number of failure modesare possible in the Blow test but in this example, adhesion of thecoating materials to the glass, adhesion of the coating materials toeach other and adhesion of the coating materials to the epoxy are thefailure modes of most interest.

Table 15 shows the CASS, Steam and Blow results, obtained with multiplesamples, for pure silver and different silver alloys. The average valuesare presented for the Steam and Blow tests, while results of the CASStests are expressed in days to failure. It is believed that ability of amaterial to survive approximately 2 days without coating damage (in CASStest) is sufficient for most vehicle interior applications. All CASStests were stopped at 17 days or 400 hours, which corresponds to arelatively long exterior vehicle test. Depending on the application theCASS requirement may vary between these two extrema. The pure silver hasthe worst performance in the steam test, relatively poor CASS results,and relatively poor adhesion in the blow tests that demonstratedsubstantial intra-coating delamination. Samples made with thetraditional dopants, Pd, Pt and Au, are also shown in Table 5.Improvements are demonstrated for the steam and blow tests relative tothe pure silver but the CASS results are still not adequate. Similarly,the AgIn alloy has improved properties in Steam and Blow but the CASSresults are improved but not adequate for all applications.

Silver alloys known as Optisil™ (supplied by APM Inc) were alsoevaluated. Three versions, 592, 595 and 598 were tested. Thecompositions are shown below in Table 16. Each version demonstratessubstantial improvement relative to the pure silver with the Optisil 598showing the best performance. The Optisil 598 has some coating lift inthe blow tests but percentage of coating lift was very small and thisalso corresponded with the highest average blow value. Therefore, eventhough some lift is present, the results do not show significant failuremode for this material. The Optisil materials are viable for interiorvehicle applications and some are viable for external applications also.A number of sterling silver alloys were tested. The specificcompositions, based on analysis of the sputtering targets, are shown inTable 16. These particular alloys show substantial improvement over thepure silver. The Sterling “88” and 51140 alloys had the best performanceof the group with the 51308 and Argentium having lesser performance. Inthe Optisil family, the lower levels of Cu and Zn provide better CASSresistance. For the Argentium, the copper and germanium additions helpimprove the CASS resistance. The “Sterling” samples benefited from theaddition of copper (all), zinc and Si (88 and 51308) and Sn (51308).

TABLE 15 Days to Failure (Results are for all parts in test unlessnoted) Steam Steam Material CASS Coating CASS Seal Day-To-Fail % Coatinglift Blow PSI Ag99.99% 1 1 4.3 30 31.2^(#) (1 part ok to (1 part ok today 12) day 12) Optisil 592 5.5 (2 part 15 20.5 0.8 32.4 average) (2parts ok to day 17) Opti 595 17 17 20.2 15.8 30.1 Optisil 598 17 17 24.30.83 41.5^(#) 83Ag/17In 1 6.25 19.7 0 37.0 Ag94/Pt6 1 1 18.7 4.235.2^(#) Ag96/Pd3 1 1 12.2 86.7 39.4^(#) Argentium 1 (2 part 5.5 (2 part27.3 0 38.1^(#) sterling average) average) (2 parts ok to (2 parts ok today 17) day 17) Sterling “88” 17 9 (2 part 21.3 0 28.5 average) (2 partsok to day 17) Sterling 7 (1 part) 7 (1 part) 23.7 0 32.1 51140* (3 partsok to (3 parts ok to day 17) day 17) Sterling 51308 8 8 20.7 8.3 34.6Ag93/Au7 1 1.33 13.3 25.8 29.2^(#) Ag16Au 2 2 18.3 22.5 30.2 Ag76/Au24 11.33 11.3 95.8 40.5 *These parts had some suspended data in steam tests,therefore actual average is higher than reported values ^(#)These parthad some intra-coating adhesion failures

TABLE 16 Silver Alloy Compositions Name Ag Cu Ge Zn Sn Si Au InArgentium 91.73 6.879 1.329 Sterling 51308 92.76 2.775 4.194 0.10970.0894 0.0153 Sterling 51140 92.18 7.779 Sterling 88 92.49 5.5403 1.88330.0422 Optisil 598 98.24 1.134 0.4805 0.088 Optisil 595 95.04 2.7611.892 0.0573 0.2066 Optisil 592 92.95 4.767 2.064 0.1183 0.0577 Ag/In82.82 0.0124 0.0056 0.0114 17.13

Degradation of a material usually occurs in multiple ways, and there areoften multiple possible protection pathways and the different elementsdoped into or alloyed with the silver can act to stabilize the metalthus improving its performance. The different silver alloys may containone or more elements that act on one or more of the protection pathwaysto stabilize the silver. Silver often degrades by migration into a lowerenergy state. The silver atoms are 100 times more mobile along theboundary of an Ag-grain than within the bulk of the grain. Therefore,addition of an element migrating to the Ag-grain boundary and inhibitingthe mobility of the silver is expected act to improve the durability ofAg. Metals such as Ti and Al are often corrosion resistant because theyoxidize and the surface oxide seals the metal preventing furtherreactions. In the case of silver, elements may be added to the metalthat act to protect the silver from the corrosive or degradation ofenvironmental stressors. In other cases an element may be added thatforms an alloy with the silver that alters the chemical or environmentalactivity of the silver. The Sterling silver alloys described above may,in part, contribute to this stabilization method. Still other methods tostabilize the silver include the use of an interface treatment as taughtin Our Prior Applications, where sulfur or other element is embeddedinto the surface of a coating or substrate prior to the deposition ofthe silver or silver alloy. Out Prior Applications also taught thedeposition of silver or a silver alloy onto a ZnO or other surface thatputs the deposited material into a low energy state, thereby improvingits environmental durability. The silver layer may also be protected bythe application of metal or non-metal (oxide, nitrides, etc) eitherabove or below the silver layer. Additionally, the silver or silveralloy may be protected by being overcoated with a relatively thick oxidelayer such as ITO. It is recognized that variation of depositionconditions such as target shielding angles, target to substratedistance, composition of residual background gasses, speed of layergrowth, e.g., may produce somewhat varying results. Nonetheless, thetrend of improvement of various characteristics for noted materialsnoted is expected to hold over a range of parameters, particularly thosetypical for magnetron sputtering.

Specific elements that may be added to the silver that can enable one ormore of the stabilization mechanisms described above include: Al, Zn,Cu, Sn, Si, Ge, Mn, Mg, W, Sb, B, Cr, Th, Ta, Li and In. These can beused either alone or in combination to enable good CASS performance,adequate Steam lifetime and good adhesion. Preferably, the CASSresistance should be greater than about 2 days, preferably greater than5 days, more preferably greater than 10 days and most preferably greaterthan 17 days. The steam lifetime should be greater than 10 days,preferably greater than 15 days, and more preferably greater than 20days. The coating stack should maintain adherence to glass, epoxy andwithin itself during adhesion tests. The blow test described abovedemonstrates relative performance among a set of samples but the test isdependent on mirror shape, pressure ramp rate, edge treatment and epoxytype as well as coating performance.

Aluminum Alloys for Corrosion Resistance.

As noted in other parts of this specification, aluminum has a highreflectance and, for that reason, is also of interest for fabrication ofa peripheral ring. Though the use of this material in peripheral ringsis known, no means of improving its chemical and environmentaldurability has been proposed. We discovered a variety of alloys ofaluminum and dopants that improve the stability of aluminum inEC-element environment. Elements such as magnesium, manganese, silicon,copper, ruthenium, titanium, copper, iron, oxygen, nitrogen or palladiumeither alone or in combination with other elements in this group willimprove the stability of the aluminum. Other elements may be present inthe aluminum without deviating from the spirit of this invention. Theamounts of these elements required for improvement of aluminum qualitiesmay be between 50 and 0.1 weight-%, preferably between 40 and 0.5weight-%, more preferably between about 25 and 0.5 weight-%, and mostpreferably between about 10 and 0.5 weight-%.

Table 17 shows the performance of different Al-based materials in theCASS test either as single layers or in stacks. The stack consists of120 nm ITO/5 nm chrome/Al-based material/35 nm chrome/5 nm ruthenium.This stack is particularly well suited for a perimeter ring. The ITOprovides the electrical conductivity for the EC-cell, the 5 nm chromelayer provided adhesion of different metals to the ITO, the Al-basedmaterial provides relatively high reflectance for the system, the 35 nmchrome provides opacity, and the 5 nm ruthenium provides good electricalconductivity and stability to a Ag-paste type electrical buss of theEC-element. The aluminum-based materials may be spatially uniform incomposition or the composition may be graded across a part. A gradedpart is one in which the composition gradually changes from onecomposition to another composition across the part. The graded parts areproduced in a combinatorial fashion using two three-inch sputtercathodes angled toward each other. The angle of the cathodes, therelative power and the composition of the targets mounted to eachcathode can be varied to alter the composition across the substrate. Therelative composition of the coating at different locations can beestimated using analytical techniques or from calibration experiments.

As shown in Table 17, the pure aluminum coating is degraded in less thana day in CASS testing. We discovered that stability of aluminum coatingsvaries with the thickness of the aluminum layer. In particular, thelifetime in CASS decreases as the thickness of the layer increases. Avery thin layer, approximately 50 angstroms, has significantly superiorstability lasting up to 17 days in CASS. We also unexpectedly discoveredthat Al deposited at high grazing angles in the combinatorial depositionsystem also had unexpectedly high stability, which can possibly beexplained by the fact that a thin metallic layer incorporates more ofthe background gas into its matrix during deposition and the traceoxygen or water present during deposition is partially oxidizes thealuminum, thereby leading to the improved CASS stability. For improvedstability, the oxygen content in the aluminum film should be below about20%, preferably below about 10%, more preferably less than about 5%, andmost preferably less than about 2.5%. The lower oxygen content has theadded benefit of having a lesser impact on the optical properties of thealuminum. Alternatively, the crystal structure of the aluminum may varywith thickness. In this case the physical thickness of the layersthemselves, rather than oxygen content is the mechanism leading toimproved stability. The aluminum layer should be less than about 70angstroms, preferably less than about 55 angstroms and most preferablyless than about 40 angstroms. The reflectance of a stack may be tailoredto a specific level by depositing a breaker layer in between multiplesilver layers such as Al/SiO₂/Al/SiO₂/Al. The breaker layer should berelatively thin to avoid thin film interference colors, i.e., less thanabout 500 angstroms, preferably less than 250 angstroms and mostpreferably less than about 100 angstroms.

We also discovered that Al:Si compound, where the Si-content varies fromabout 40% to 10%, performs substantially better than the pure aluminum.The higher Si level of about 40% has CASS performance that isindependent of thickness, while the lower Si content material (at about10% level) demonstrates the CASS stability versus thickness of the layersimilar to that of the pure aluminum.

Aluminum-titanium compounds were also evaluated. Titanium contentsbetween about 50% and 25% show substantially improved CASS stability.Ruthenium added to AlTi or other aluminum compounds also substantiallyimproved the performance even at very small levels. This additive, alongwith Pd, is expected to lead to improved CASS results in variousaluminum-based materials.

TABLE 17 Metal Metal Thickness Stack Details (angstroms) CASSPerformance ITO/Cr/Metal/Cr/Ru Al 140   <1 day ITO/Cr/Metal/Cr/Ru AlTi70:30 ~150-200   14 days ITO/Cr/Metal/Cr/Ru AlTi 50:50 ~150-200   14days ITO/Cr/Metal/Cr/Ru AlTi 75:25 ~150-200   14 days ITO/Cr/Metal/Cr/RuAl 94  <1 day ITO/Cr/Metal/Cr/Ru Al 70  <1 day ITO/Cr/Metal/Cr/Ru Al 56   2 days ITO/Cr/Metal/Cr/Ru Al 47 very light damage up to 21 daysITO/Cr/Metal/Cr/Ru Al 40 very light damage up to 21 daysITO/Cr/Metal/Cr/Ru Al:Si 60:40 140  >21 days ITO/Cr/Metal/Cr/Ru Al:Si60:41 105  >21 days ITO/Cr/Metal/Cr/Ru Al:Si 60:42 84 >21 daysITO/Cr/Metal/Cr/Ru Al:Si 60:43 70 >21 days ITO/Cr/Metal/Cr/Ru Al:Si60:44 60 >21 days ITO/Cr/Metal/Cr/Ru AlTiRu ~150-200 >17ITO/Cr/Metal/Cr/Ru AlTiRu ~150-200 >17 90:8:2

Optical properties of aluminum may be affected by added elements. Table18 shows the refractive index of some of the aluminum-based materials.These values may be used in conjunction with thereflectance-enhancement-metal (REM) formula described above to determinethe arrangements wherein these materials can be used to increase thereflectance of Al-based film.

TABLE 18 Material N K Al60/Si40 3.13 4.49 Al90/Si10 1.24 4.94 Ti50/Al502.54 2.96 Ti30/Al70 2.88 3.39Other Materials Viable as REM with CASS ResistanceCopper alloys of Zinc and tin, known as brass and bronze, respectively,have good optical properties and function well as REM layers for a widerange of base metals and, depending on the composition, can have goodCASS resistance. Navel brass, with a 60:40 Cu:Zn ratio and other traceelements, lasted up to 7 days in CASS while Cu:Sn at a 50:50 ratio alsosurvived up to 7 days in CASS (both in a ITO/Cr/Metal/Cr/Ru stackdescribed above for Al. It is expected that select alloys and compoundof copper, alloyed with other elements will be suitable for use as REMlayers. The homogeneous peripheral ring embodiments described herein areoften preferred to match the reflectivity and color of the main mirrorreflector. The color tolerancing described elsewhere in this documentmay be preferred in some applications. Additives to make brass morecorrosion resistant include iron, aluminium, silicon nickel, tin andmanganese. In certain applications, where a single phase is present inthe brass, phosphorus, arsenic or antimony in levels of less than 0.1%can provide further stability. In some embodiments, having a zinccontent of less than 15% may also provide benefits. Brasses knowncommonly as “Admiralty” or “Navel” brass may be particularly stable incorrosive environments. Bismuth bronze, a copper/zinc alloy with acomposition of 52 parts copper, 30 part nickel, 12 parts zinc, 5 partslead, and 1 part bismuth is quite stable. It is able to hold a goodpolish and so is sometimes used in light reflectors and mirrors.Additives to make copper-tin bronzes more corrosion resistant includephosphorus, zinc, aluminum, iron, lead, and nickel.

The homogeneous ring embodiments described herein are often preferred tomatch the reflectivity and color of the main mirror reflector. The colortolerancing described elsewhere in this document may be preferred insome applications.

Universal Thin Film Stacks.

The durable silver- and aluminum-based alloys are particularly useful asso-called universal materials. Depending on the requirements of aparticular application, the reflectivity and color of the peripheralring may vary. As more reflectivity levels of the ring are requested bythe users, manufacturing of peripheral rings becomes challenging ifmultiple metals are needed to attain the desired reflectivityproperties. If, for instance, different embodiments or applicationsrequire 35%, 45%, 55%, 65%, 75% or 85% reflectance, then up to 6different materials could be used to attain the desired color match. Itis often easier to lower the reflectance of a high reflectance metalrather than raise the reflectance of a lower reflectance metal.Therefore, in certain manufacturing scenarios a range of reflectancevalues can be obtained with a high reflectance metal by either reducingthe thickness of the metal and optionally backing the layer with a lowtransmittance metal when opacity is needed. The REM formula describedabove can be used to assist selecting appropriate metal combinations.Another way to lower the reflectance of a high reflectance metal is toput a lower reflectance metal in front of it (relative to the viewer).The thickness of the lower reflectance metal can be increased todecrease the reflectance of the high reflectance metal. The silver andaluminum alloys described herein are particularly good in that they haveexcellent environmental durability, adhesion and high reflectance.Therefore, in a production environment, a number of commercial productsmay be produced simply by adjusting the thickness of a single layer.This leads to a particularly simple process for manufacturing thusreducing capital cost, development time and product durability.

Electrochromic Medium.

Preferably the chamber contains an electrochromic medium. Electrochromicmedium is preferably capable of selectively attenuating light travelingtherethrough and preferably has at least one solution-phaseelectrochromic material and preferably at least one additionalelectroactive material that may be solution-phase, surface-confined, orone that plates out onto a surface. However, the presently preferredmedia are solution-phase redox electrochromics, such as those disclosedin commonly assigned U.S. Pat. Nos. 4,902,108, 5,128,799, 5,278,693,5,280,380, 5,282,077, 5,294,376, 5,336,448, 5,808,778 and 6,020,987; theentire disclosures of which are incorporated herein in their entiretiesby reference. If a solution-phase electrochromic medium is utilized, itmay be inserted into the chamber through a sealable fill port throughwell-known techniques, such as vacuum backfilling and the like.

Electrochromic medium preferably includes electrochromic anodic andcathodic materials that can be grouped into the following categories:

(i) Single layer—the electrochromic medium is a single layer of materialwhich may include small inhomogeneous regions and includessolution-phase devices where a material is contained in solution in theionically conducting electrolyte and remains in solution in theelectrolyte when electrochemically oxidized or reduced. U.S. Pat. Nos.6,193,912; 6,188,505; 6,262,832; 6,129,507; 6,392,783; and 6,249,369disclose anodic and cathodic materials that may be used in a singlelayer electrochromic medium, the entire disclosures of which areincorporated herein by reference. Solution-phase electroactive materialsmay be contained in the continuous solution phase of a cross-linkedpolymer matrix in accordance with the teachings of U.S. Pat. No.5,928,572 or International Patent Application No. PCT/US98/05570entitled “ELECTROCHROMIC POLYMERIC SOLID FILMS, MANUFACTURINGELECTROCHROMIC DEVICES USING SUCH SOLID FILMS, AND PROCESSES FOR MAKINGSUCH SOLID FILMS AND DEVICES,” the entire disclosures of which areincorporated herein by reference.

At least three electroactive materials, at least two of which areelectrochromic, can be combined to give a pre-selected color asdescribed in U.S. Pat. No. 6,020,987 the entire disclosure of which isincorporated herein by reference. This ability to select the color ofthe electrochromic medium is particularly advantageous when designinginformation displays with associated elements.

The anodic and cathodic materials can be combined or linked by abridging unit as described in International Application No.PCT/WO97/EP498 entitled “ELECTROCHROMIC SYSTEM,” the entire disclosureof which is incorporated herein by reference. It is also possible tolink anodic materials or cathodic materials by similar methods. Theconcepts described in these applications can further be combined toyield a variety of electrochromic materials that are linked.

Additionally, a single layer medium includes the medium where the anodicand cathodic materials can be incorporated into the polymer matrix asdescribed in International Application No. PCT/WO98/EP3862 entitled“ELECTROCHROMIC POLYMER SYSTEM,” U.S. Pat. No. 6,002,511, orInternational Patent Application No. PCT/US98/05570 entitled“ELECTROCHROMIC POLYMERIC SOLID FILMS, MANUFACTURING ELECTROCHROMICDEVICES USING SUCH SOLID FILMS, AND PROCESSES FOR MAKING SUCH SOLIDFILMS AND DEVICES,” the entire disclosures of which are incorporatedherein by reference.

Also included is a medium where one or more materials in the mediumundergoes a change in phase during the operation of the device, forexample, a deposition system where a material contained in solution inthe ionically conducting electrolyte which forms a layer, or partiallayer on the electronically conducting electrode when electrochemicallyoxidized or reduced.

Multilayer—the medium is made up in layers and includes at least onematerial attached directly to an electronically conducting electrode orconfined in close proximity thereto which remains attached or confinedwhen electrochemically oxidized or reduced. Examples of this type ofelectrochromic medium are the metal oxide films, such as tungsten oxide,iridium oxide, nickel oxide, and vanadium oxide. A medium, whichcontains one or more organic electrochromic layers, such aspolythiophene, polyaniline, or polypyrrole attached to the electrode,would also be considered a multilayer medium.

In addition, the electrochromic medium may also contain other materials,such as light absorbers, light stabilizers, thermal stabilizers,antioxidants, thickeners, or viscosity modifiers.

It may be desirable to incorporate a gel into the electrochromic deviceas disclosed in commonly assigned U.S. Pat. No. 5,940,201, the entiredisclosure of which is incorporated herein by reference.

In at least one embodiment, a rearview mirror assembly is provided withan electro-optic element having a substantially transparent seal.Examples of substantially transparent seals and methods of formingsubstantially transparent seals are provided in U.S. Pat. No. 5,790,298,the entire disclosure of which is included herein by reference.

In at least one embodiment, the rearview mirror assembly is providedwith a bezel 6580 for protecting the associated seal from damaging lightrays and to provide an aesthetically pleasing appearance. Examples ofvarious bezels are disclosed in U.S. Pat. Nos. 5,448,397, 6,102,546,6,195,194, 5,923,457, 6,238,898, 6,170,956 and 6,471,362, thedisclosures of which are incorporated herein in their entireties byreference.

It should be understood that the above description and the accompanyingfigures are for illustrative purposes and should in no way be construedas limiting the invention to the particular embodiments shown anddescribed. The appending claims shall be construed to include allequivalents within the scope of the doctrine of equivalents andapplicable patent laws and rules.

What is claimed is:
 1. A vehicular rearview assembly having a front andfront peripheral region, the assembly comprising: a first substrateincluding a first surface corresponding to the front; a second surface;and a first transparent electrically conductive electrode layer carriedon the second surface; a second substrate including a third surface; anda fourth surface; and an at least partially reflective stack ofmaterials carried on at least a portion of at least one of the thirdsurface and the fourth surface; a perimeter seal between the firstsubstrate and second substrate; wherein the first substrate, secondsubstrate, and the perimeter seal define a cavity; an electro-opticmedium disposed in the cavity between the first substrate and the secondsubstrate and bounded by the perimeter seal; and a ring of spectralfilter material disposed circumferentially at a periphery area of thefirst substrate on at least one of the first surface and the secondsurface, wherein a diffuse reflectance at the periphery area of thefirst substrate is greater than a specular reflectance by at least about3 L* units.
 2. A rearview assembly according to claim 1, wherein thediffuse reflectance associated with the periphery area is defined by anelement including at least one of (i) a material deposited in theperiphery area of the first substrate (ii) an area of the firstsubstrate a surface texture of which has been modified, in the peripheryarea, as compared to an original surface texture of the area, and (iii)an intermediate layer that includes one or more of (iiia) a transparentmaterial layer, (iiib) a semi-translucent material layer including smallparticles therein, and (iiib) a semi-transparent layer a texture ofwhich differs from that of a surface of the first substrate in theperiphery area, the intermediate layer disposed in the periphery area.3. A rearview assembly according to claim 2, wherein the diffusereflectance is associated with the first surface.
 4. A rearview assemblyaccording to claim 2, wherein the diffuse reflectance is associated withthe second surface.
 5. A rearview assembly according to claim 2, whereinthe element defining the diffuse reflectance is behind the ring ofspectral filter material with respect to the front.
 6. A rearviewassembly according to claim 2, wherein the element defining the diffusereflectance is in front of the ring of spectral filter material withrespect to the front.
 7. A rearview assembly according to claim 1,wherein the electro-optic medium include electrochromic medium.
 8. Arearview assembly according to claim 1, further comprising a secondtransparent electrode layer carried by the third surface, wherein thetransparent second electrode layer includes a transparent conductiveoxide (TCO).
 9. A rearview assembly according to claim 8, wherein theTCO includes one or more of ITO, F:Sn02, Sb:Sn02, Doped ZnO such asAl:ZnO, Ga:ZnO, B:ZnO, and IZO.
 10. A rearview assembly according toclaim 8, wherein at least a portion of the third surface carried the atleast partially reflective stack of materials, the stack including thesecond transparent electrode layer.
 11. A rearview assembly according toclaim 1, wherein the at least partially reflective stack of materialsincludes at least one of Al90/Si10, Cr, Brass, Ti, AgAu7X, Ru, Ni, TiO2,and SiO2.
 12. A rearview assembly according to claim 1, wherein the ringof spectral filter material includes one or more of a dielectric layer,silver, chrome, black chrome, ruthenium, stainless steel, silicon,titanium, nickel, molybdenum, nickel chromium, Inconel, indium,palladium, osmium, cobalt, cadmium, niobium, brass, bronze, tungsten,rhenium, iridium, aluminum, aluminum alloy, scandium, yttrium,zirconium, vanadium, manganese, iron, zinc, tin, lead, bismuth,antimony, rhodium, tantalum, copper, gold, platinum, a platinum groupmetals, an oxide thereof, and an alloy thereof.
 13. A rearview assemblyaccording to claim 1, wherein the diffuse reflectance at the peripheryarea of the first substrate is greater than a specular reflectance by atleast about 10 L* units.
 14. A rearview assembly according to claim 1,wherein the diffuse reflectance at the periphery area of the firstsubstrate is greater than a specular reflectance by at least about 20 L*units.
 15. A rearview assembly according to claim 1, wherein the diffusereflectance at the periphery area of the first substrate is greater thana specular reflectance by at least about 50 L* units.
 16. A rearviewassembly according to claim 1, wherein a color difference between theperipheral region containing the ring of spectral filter material and aregion of the assembly encircled by the ring is less than 30 C* units,wherein C* is a metric defined according to CIELAB based on a CIEstandard D665 illuminant and a 10-degree observer.
 17. A rearviewassembly according to claim 1, wherein the front peripheral region ischaracterized by a radius of curvature of at least 2.5 mm.
 18. Arearview assembly according to claim 1, wherein the front peripheralregion is defined by a surface of glass having a radius of curvature ofat least 2.5 mm.
 19. A rearview assembly according to claim 1, whereinthe front peripheral region includes a bezel element having a radius ofcurvature of at least 2.5 mm.
 20. A vehicular rearview assembly having afront and front peripheral region, the assembly comprising: a firstsubstrate including a first surface corresponding to the front; a secondsurface; and a first transparent electrically conductive electrode layercarried on the second surface; a second substrate including: a thirdsurface; a fourth surface; and an at least partially reflective stack ofmaterials carried on at least a portion of at least one of the thirdsurface and the fourth surface; a perimeter seal between the firstsubstrate and second substrate, wherein the first substrate, secondsubstrate, and the perimeter seal define a cavity; an electro-opticmedium disposed in the cavity between the first substrate and the secondsubstrate and bounded by the perimeter seal; and a ring of spectralfilter material disposed circumferentially at a periphery area of thefirst substrate on at least one of the first surface and the secondsurface, wherein the reflectance value of the periphery areacorresponding to the ring is less than 50% as measured in ambient lightincident onto the first surface from the front.